IhL 70, No. 3, pp. 299-322 W004 Council for Exceptional ChlUrm.

What Research Says About Vocabulary Instruction for Students With Learning Disabilities ASHA K. JITENDRA

LANA L. EDWARDS

GABRICLL SACKS

Lehigh University, Pennsylvania LISA A. JACOBSON

SchuyIkill Va& Sschool District, Pennsylvania

ABSTRACT: This article summarizes published research on vocabulary instruction involving students with learning disabilities. Nineteen vocabulary studies that comprised 27 investigations were lo- cated Study interventions gleaned from the review included keyword or mnemonic approaches, cognitive strategy instruction (e.g., semantic features analysis), direct instruction (Dl), constant time delay (CTD), activity-based methods, and computer-assisted instruction (CAI). While find- ings for the keyword, cognitive strategy, Dl, CTD, and activity-basedprocedures wen generally of- fictive in enhancing vocabulary performance for students with learning disabilities, results for CAI were mixed. The studies are discussed with regard to study characteristics (e.g., intervention inten- sig instructional arrangement). Implications and recommendations for future research and class- room practice in teaching vocabulary to students with learning disabilities are discussed

T he importance of vocabulary knowledge to school success, in general, and reading comprehen- sion, in particular, is widely doc- umented (Anderson & Nagy,

1991; Baker, Simmons, & Kame'enui, 1998; Becker, 1977; Cunningham & Stanovich, 1998). Further, the recent RAND report, Reading for Understanding, suggests that vocabulary and word knowledge can contribute to improved compre- hension, and it provides a sound rationale for in- creased emphasis on vocabulary instruction

(Snow, 2002). While vocabulary knowledge is fundamental to reading comprehension (Bau- mann & Kame'enui, 1991; Stanovich, 1986), ex- isting research does not support a specific vocabulary development method or program to address the discrepancies in word knowledge be- tween students with poor and rich vocabularies (Baker, Simmons, & Kame'enui, 1998; National Research Council, 1998; Snow, 2002). Rather, the development of proficient reading skills is documented as the most effective independent word learning strategy.

I

important words or words that students will en- counter often (Stahl, 1986). Explicit instruction should also include the use of a word's context and definition, opportunities for "deep process- ing" (e.g., finding a synonym or antonym, mak- ing up a novel sentence with the word, classifying the word with other words, and relating the defi- nition to one's own experience), and multiple ex- posures to the new word (Stahl). Finally, vocabulary should be taught through productive approaches that optimize word learning (Snow, 2002). For example, rather than focusing on a set of targeted words, instruction might focus on one word with multiple semantic connections to other words (Stahl & Shiel). Productive approaches might include teaching students strategies to learn words from context, word parts (e.g., decompos- ing words to examine affixes and roots), or se- mantic mapping (Baumann & Kame'enui, 199 1).

Given that students with learning disabili- ties often have inadequate vocabulary knowledge and difficulties with learning as a language-based activity, it is critical to examine what research says about vocabulary instruction, specifically for stu- dents with learning disabilities. Although previous reviews of vocabulary instruction are available, they have focused exclusively on students without disabilities (e.g., Baumann & Kame'enui, 199 1 ; National Reading Panel, 2000; Stahl & Fair- banks, 1986). A review of vocabulary instruction for students with learning disabilities is lacking even though a reasonable number of vocabulary intervention studies with samples of students with learning disabilities is available. Therefore, the purpose of this review is to summarize the find- ings of vocabulary intervention research studies designed for students with learning disabilities to document effective and productive approaches to word learning and to provide directions for class-

Research on the richness of vocabulary used in sources of spoken and written language has revealed that speech i f

alexicaUy impovenShed" when com- pared to written language.

room practice and future research in vocabulary instruction.

M E T H O D S

Computer searches of PsycINFO and ERIC data- bases from 1978 to 2002 were conducted to lo- cate appropriate studies. Descriptors for the computer search included "reading," and "vocab- ulary or concepts," "concept mapping or semantic mapping," or "mnemonics," and "instruction, in- terventions, or strategies," and "disabilities." In additipn, we carefully examined the references from the identified studies themselves. Finally, we hand-searched the following journals to locate the most recent literature: Education and Treatment of ChiIllren, Exceptional ChiIllren, Journal of Learning Disabilities, The Journal of Special Education, Learning Disability Quarter& Learning Disabilities Research and Practice, Reading and Writing Quar- terly. Overcoming Learning Difficulties, and Reme- dial and Special Ed.ucation. It must be noted that we did not include other sources of the literature (e.g., Dissertation Abstracts International) or con- tact active researchers in this area for unpublished studies. As such, conclusions based on this review should be viewed as tentative.

To judge the appropriateness of each article, we evaluated studies using six criteria. First, only published studies were included in the review. Unpublished doctoral dissertations and presenta- tions were excluded. Thus, the review may repre- sent a potential bias toward more sound research designs and stronger effect sizes than perhaps are found in unpublished articles (Lipsey & Wilson, 1993). Second, experimental, quasi-experimental, and single-subject design studies were included in the review. Third, the recipients of the interven- tion were identified as children with learning dis- abilities. Fourth, the studies had to include elementary, junior high, or high school students with learning disabilities. Fifth, studies that de- scribed vocabulary instruction related to sight word reading (e.g., Keel, Slaton, & Blackhurst, 2001) rather than word knowledge (meaning) and/or did not present evidence of the effects of

tf * systematic use of vocabulary strategies on vocabu- lary learning were excluded. For example, al- though the Reyes, Duran, and Bos (1989) study addressed vocabulary strategies, it was not in- cluded because the primary purpose of this study was to determine the effects of code switching or language alternation on the vocabulary perfor- mance of bilingual students with learning disabili- ties. Finally, studies included in this review had to measure vocabulary outcomes. Interrater agree- ment for article inclusion and exclusion was 96% (range = 90% to 100%).

Using these criteria, a total of 20 studies were located. However, the final review included 19 relevant vocabulary studies, because 1 study (Woodward, Carnine, & Collins, 1988) reported data from a previous study (Johnson, Gersten, & Carnine, 1987). Interrater agreement on coding of pertinent sample and study characteristics for each study was conducted. The mean interrater agreement was 93% (range = 74% to 100%). We calculated and reported effect sizes (ES) or per- centage of nonoverlapping data (PND) when suf- ficient data (e.g., means and standard deviations, clear graphs and charts) were provided for group and single-subject design studies. Group effects were calculated using Cohens d, in which ES = M posttest score of the experimental group - M posttest score of the control grouplpooled stan- dard deviation. In some situations in which means and standard deviations were not provided, effect sizes were calculated using F o r t-test scores provided (see Murawski & Swanson, 2001). When a study did not include a control group and used a pretest-posttest research design on the treatment group only, we used the standardized mean change to calculate the intervention effect (Becker, 1988). The effect size in such instances was determined by computing the difference be- tween the posttest and pretest means divided by the pretest standard deviation.

R E S U L T S

This review of 19 studies included 17 (89.5%) gmup design studies and 2 (10.5%) single-subject design study. Of these studies, 12 were published

from 1978 to 1989 and 7 were published from 1990 to 1996. Three studies included two experi- ments (Boettcher, 1983; Horton, Lovitt, & Givens, 1988; Mastropieri, Scruggs, Levin, Gaffney, & McLoone, 1985), 1 study included three experiments (Pany, Jenkins, & Schrek, 1982), and 1 study included six experiments (Bos & Anders, 1992). However, Experiment 2 in the study by Horton et al. and Experiment 1 in the Pany et al. study included only students without disabilities. As such, these were not included in the review. The 19 articles yielded a final sample of 27 investigations. A total of 901 students with learning disabilities participated in the studies re- viewed.

Sixteen investigations reported specific grade levels with ranges of Grades 4 through 12, and 19 investigations reported participants' ages with ranges of 9 to 16.2 years. Twelve investiga- tions reported the gender of participants (229 males and 96 females). The length of interven- tions varied from 1 session to 15 sessions (M =

5.25; SD = 3.71, n = 26) and session duration ranged from 2 min to 50 min (M = 36.20; SD =

16.54, n = 20). Regarding intervention setting, 30% were conducted in special education class- rooms; 1 1 % in content area classrooms; and 18% in a library, a computer lab, or quiet rooms adja- cent to the classroom. Eleven investigations (41%) did not report the settings in which the re- search was conducted. With regard to delivery of instruction, researchers (52%) most often deliv- ered the instruction, followed by teachers (26%), computers (19%), and a librarian (4%). In gen- eral, instruction occurred most often in groups (63%), followed by individual instruction (33%) and instruction in pairs (4%). While the majority of investigations (78%) did not provide any treat- ment fidelity information, 1 investigation (4%) reported high treatment fidelity of 98%, 4 inves- tigations (15%) indicated that a checklist or teaching script was developed to ensure treatment consistency, and 1 investigation (4%) reported using videotaping to ensure treatment fidelity. Only 2 investigations (7%) reported reliability data for the dependent measures. Transfer data were collected in 8 investigations (30%). Mainte- nance data were collected in 15 investigations (56%). Twenty-five investigations (93%) em-

TABLE 1

Summary of Interventions Citation Sample Exper imenta l In tervent ion Description; Dependent Measures

Results

Description Design Duration -I

Andcrs, Bas, 62 students with Two intact sp. ed.. Vocabulary look-up vs. 20-item multiple Posttest: O n total comprehension test, SPA > the vocabulary look-up (ES =1.70). O n vocabulary items, SFA > the vocabulary look-up (ES =1.35). O n & Filip

(1 984)

Boettcher (1983)

Study I

Study 2

LD; M age = NA; I Q = 85- 1 15; Reading' = 3 -7 years below grade level; Grades: 9- 12

28 students with LD;Mage= 11- 13 years.; 1Q = below normal; Reading' = 2.5- 3.0 grade; Grades: 4 to 6

22 students with LD; M age = 7-0 13 yrs., l Q = NA; Reading' = 2.0-6.2 grade; Grades: NA

assigned to 2 conditions and blocked by grade. Teachers randomly assigned to the two groups.

classes randomly semantic features choice social studies

One group pretest/posttest

analysis (SFA). passage comprehension test,

4 sessions over 2 weeks; 10 each of 50 min each. vocabulary and

conceptual (apply concepts to specific situations) items.

Reading Vocabulary and Comprehension System reading (RCS) CAI program. comprehension

subtests of Level 13 45 min per week over 9 of the CAT. weeks; total time = 6.8 hrs.

Same as Study 1. Mean total time = 7.4 Same as Study 1. hrs over 9 months.

conceptual items, SFA > the vocabulary look-up (ES = 1.52).

Follow-up: NA

Transfer: NA

Posttest: All students gained an average of close to or over 1 year or more on both vocabulary (M = + 1.32) & comprehension tests (M = + 1.58).

Follow-up: NA

Transfer: NA

Posttest: Pre-post gains on the standardized test were its.

Follow-up: NA

Transfer: NA

female); M age = randomly assigned 13.8 years; 1Q = to four treatment 88.67; ~ e a d i n ~ ' groups. = 8 1.30; Grade: junior high

r b a d Students assigned 42 bilingual to one of four :English/ conditions. Spanish) students with LD; M age : 1 1.36; I Q per0 = 96.93; heading* = '5.98; Grade: ippcr elementary

1 students with Students assigned .D; M age = to one of four 3.80 years; IQ conditions. d l ) = 9 1.97; .cadingl = . -- - -

vs. semantic mapping (SM) vs. semantic feature analysis (SFA) vs. syntacticlsemantic feature analysis (SSFA).

8 sessions over 7 weeks; 50 min each.

Semantic mapping (SM) vs. semantic feature analysis (SFA) vs. semanticlsyntactic feature analysis (SSFA) vs. definition instruction (Dl).

6 sessions; 50 min each.

Same as in Expt. I

6 sessions; 50 min each.

choice science passage comprehension test (1 5 context-related voc. knowledge items and 15 comp. items measured voc. usage); written recalls (relevant voc., conceptual units, quality scriptal knowledge, & holistic ratings).

A 20- to 30-item multiple choice test with voc. and comp. items.

A 20- to 30-item multiple choice test with voc. and comp. items.

'Continued) 61 students with Four-group Direct instruction (Dl) 30-item multiple Posttest: On voc. test, SFA > DI (ES = 1.06); SM > Dl (ES = 1.25); SSFA > LD (41 male, 20 design. Students Dl (ES = 0.58, p = ns). On comprehension items, SSFA > Dl (ES = 1.22);

SFA > Dl (ES = 1.50, p = ns): SM > Dl (ES = 1.20, p = ns).

4-week follow-up test: On voc. test, SFA > SM > SSFA > Dl (ES: SFA vs. Dl = .68; SM vs. Dl = .93; SSFA vs. Dl = 1.41). On comp. test, SSFA > Dl (ES = 1.44); SM > Dl (ES = 0.50, p = ns); SFA > Dl (ES = 0.54, p = ns). On rel. VOC., SSFA > Dl (ES = 1.89); SFA > DI (ES = 1.42); SM > Dl (ES = 1.02, p = ns). On conceptual units, SSFA < Dl (ES = 2.48); SFA > Dl (ES = 1.83); SM > DI (ES = 1.58, p = ns). On quality scriptal knowledge, SSFA > SFA > SM > Dl (mean ES =1.40). SSFA vs. Dl (ES = 1.5 1 ); SFA vs. Dl (ES = 1.29); SM vs. Dl (ES = 1.39). On holistic ratings, SFA > Dl (ES = 1.29); SSFA > Dl (ES = 1.57); SM > Dl (ES = 1.1 l , p = ns).

Transfer: Differences among the four conditions on all measures of written recalls were ns. On rel. vocabulary, SSFA > Dl (ES = 1.89); SFA > Dl (ES = 1.42); SM > Dl (ES = 1.02). On re[. conceptual units, SSFA > Dl (ES = 2.48); SPA > DI (ES sl.83); SM > DI (ES = 1.58). On quality scriptal knowledge, SSFA < Dl (ES = -0.03); SFA < Dl (ES = -.09); SM > Dl (ES = 0.38). On holistic ratings, SSFA > Dl (ES = 0.07); SFA < Dl (ES = - 0.04); SM > Dl (ES = 0.39).

Posttest: SM, SFA, and SSFA > Dl (mean ES = 0.50 for vocabulary and 0.81 for comprehension).

4 week follow-up: SM, SPA, SSFA > DI (mean ES = 1.15 for voc. and 0.86 for comprehension).

Transfer: NA

Posttest: SM, SFA, and SSFA > DI (mean ES = 0.92 for voc. and 1.22 for comprehension).

spanish) students with LD; M age

NA; I Q = 36.93; ~ e a d i n g = 75.98; Grade: ippcr elementary

i0 students with -D; M age = 6.2 years.; I Q = 15 to 115; leading' = 1.3- 7 ¥ear below grade el; Grade: igh school

84 students with .D (48 male, 12 :male); M age = 2.6 years.; I Q = vcragc; Reading* 3.6 grade;

irade: lementary

by language (Spanish or English support) of instruction and assigned to one of four instruct-ional groups.

Intact social studies and English classes randomly assigned to an experimental or a control condition.

Four-group pretestlposttest design. 32 students with high-receptive & 32 students with low-receptive vocabularies randomly assigned to one of 4 conditions.

vs. semantic mapping (SM) vs. semantic feature analysis (SFA) vs. syntacticlsemantic feature analysis (SFAA).

8 sessions over 8 weeks; 50 min each.

Semantic feature analysis (SFA) vs. dictionary method (DM).

4 sessions over 2 weeks; 50 min each.

Keyword-image (KI) vs. picture context (PC) vs. sentence-experience context (SE) vs. control (C)

choice content test (1 5 context-related voc. knowledge items and 15 comp. items measured voc. usage); written recalls.

30-item multiple choice comprehension (1 0 vocabulary items and 10 conceptual items) test.

50-item multiple choice word knowledge tests.

15 sessions; 3 days per week over 5 weeks; 20 min each.

ontinued) 42 bilingual Students blocked Direct instruction (Dl) 30-item multiple Posttesc On the voc. test, SSFA > Dl (ES = 0.66); SM > Dl (ES = 0.87, p = (English1 ns); SFA > Dl (ES = 0.70, p = ns). On the comprehension test, SM > Dl (ES =

0.87); SFA > DI (ES = 1.03); and SSFA > Dl (ES = 0.69,) = ns).

4-week follow-up: On the voc. test, SSFA > Dl (ES = 1.22); SM > DI (ES = 1.01, p = ns); SFA > Dl (ES = 1.00, p = ns). On the comprehension test, SSFA > Dl (ES = 1.01, p = ns), SPA > DI (ES = 1.07); SM > DI (ES = 1.01). Written recalls poorer at follow-up than at posttest.

Transfer: Differences among groups on written recalls were ns. On conceptual units, SSFA < Dl (ES = -0.10); SPA > Dl (ES = 0.35); SM > Dl (ES = 0.16). On holistic ratings. SSFA > Dl (ES = 0.60); SFA > Dl (ES = 0.52); SM > Dl (ES = 0.08).

Posttest: SFA > DM on vocabulary (ES = 1.64) and conceptual items (ES = 1.63).

6-month follow-up: No significant loss or gain for either condition over time.

Transfer: NA

Posttesc KI > PC > SE > C; PC > C; SE > C. Students with high-receptive lane. > low-receptive lang. in all conditions.

2-week and 10-week follow-up: KI > PC > SE > C. On the 8-week follow-up test, students with low-receptive voc. > students with both high- and low- receptive voc. in all conditions.

Transfer: NA

TABLE I (Continued) Koury 123 students (71 Three-group Group I (52 gen. ed Paperlpencil word Posttest: Group I11 < Group I1 (ES = - 2.02); Group I11 < Group I (ES = - ( 1996) male, 52 female); posttest only students) pretaught knowledge test 1.79) on knowledge test. Differences between Group I and Group I1 were ns.

19 with LD; M design. content voc. without (define 10 pretaught age = NA; I Q = video anchors vs. science terms and Follow-up: NA NA; Reading" = Group I1 (52 gen. ed give one example of at least 1.65 SD students) pretaught each). Transfer: NA below mean. with video anchors vs. Grade: 5 Group I11 (19 students

with LD) pretaught with video anchors.

3 sessions; 40 min each.

Mastropieri, Scruggs, & Fulk (1990)

Mastropieri, Scruggs, Levin, Gaffney, & McLoone (1 985)

Expt. 1

25 students with Two-group design; LD (17 male, 8 Students stratified female); M age = by grade level and 14.1 years.; I Q = randomly assigned 92.5; Reading' = to either of 2 5.0 grade; conditions. Grades: 6 , 7 , 8

32 students with LD (21 male, 1 1 female); M age = 13.1 1 years.; IQ = 95.6; Reading' = 25th percentile; Grades: 7 , 8 , 9

Two-group posttest design. Students stratified by grade level and randomly assigned to two experimental conditions.

Keyword (KW) method vs. direct instruction (DI) rehearsal procedure.

1 session; 13 min.

Mnemonic (MN) instruction vs. direct instruction (DI).

1 session.

A literal recall (orally define each vocabulary word) test and a comprehension (identify) test of vocabulary usage using a matching format.

14-item definition recall test.

Posttest: On the recall production test, KW > DI (ES = 2.80). On the comprehension test, KW > DI (ES = 1.80). Main effect was found for item type on production tests only, with students performing higher on concrete words.

Follow-up: NA

Transfer: NA

Posttest: MN > DI on mean recall (ES = 2.52).

Follow-up: NA

Transfer: NA

Expt. 2 37 students with Same as Expt. 1. Mnemonic imagery Same as Expt. 1. Posttest: MI > DI on mean recall (ES = 0.98). LD (23 male, 7 (MI) instruction vs. female); M age = direct instruction (DI). Follow-up: NA 13.10 years.; I Q = 96.5; Reading" 1 session. Transfer: NA = 28th percentile; Grades: 7 ,8,9.

TABLE i (Continued) McLoone, 60 students with Two-group Mnemonic (MN) 14-item definition Posttest: MN > DR on mean recall (ES = 3.13). Scruggs, LD, M age = Mastropieri, 13.8 years.; IQ = & Zucker 96.22; Reading' ( 1986) = 28th percentile

(9 1 Yo < grade level); Voc." = 30th percentile (88% < grade level); Grades: 7 & 8

Pany & 6 students with Jenkins LD (I male, 5 (1978) female); M age =

9-1 1 years.; 1 Q =

normal; Median oral reading rare = 70 wcpm; Grades: 4 & 5

Pany, Jenkins, 6 students with & Schreck LD (2 male, 4 (1 982) female); M age =

Expt. 2 10 years.; I Q = normal; Reading cornp.' = 1.1 to 2.6 years below grade level; Grades: 4, 5 , 6

posttest only design, with students stratified by grade level and randomly assigned to one of two experimental conditions.

Repeated measures randomized block factorial design; each student served as own control and participated in all three treatments.

Incomplete randomized block design. Students served as own controls and participated in all conditions.

. . instruction vs. directed rehearsal (DR).

1 session; 25 min each.

Meaning from context (MC) vs. meanings given (MG) vs. meanings practiced (MP).

1 to 4 days.

Meanings from context (MC) vs. meanings given (MG) vs. meanings practiced (MP) vs. no meaning control (NM).

3 sessions; about 2 min each.

recall test; 10-item transfer items recall test.

6-item isolated voc. know. test; 6-item voc. in context test, with 3 prod. & 3 selection items (state or select synonym for target word given in a sentence); 10-item story comp. factual recall test.

6-item isolated word vocabulary test; multiple choice voc. test; sentence paraphrase test (restate sentence using target word); sentence anomaly test (select sentence that makes sense from 4 choices).

- Follow-up: NA

Transfer: M N > DR on transfer test (ES = 2.98).

Posttest: O n isolated voc. test. MP > M C (ES = 5.16); MP > MG (ES = 4.30); MG > M C (ES = 0.55, p = ns). O n the voc. in context test, M P > M C (ES = 4.62); M P > MG (ES = 3.61); MG > M C (ES = 0.86, p = m). M P posttest scores > MP pretest scores (ES = 4.01); MG posttest scores > M G pretest scores (ES = 1.52) on the voc. in context test.

3- to 8-week follow-up: MP > M C (ES = 3.65); MP > M G (ES = 2.89); M G > M C (ES = 0.34, p = m) on delayed isolated vocabulary test.

Transfer: Treatment effects on story comp. factual recall were ns, MP > M C (ES = 0.43); MP > M G (ES = 0.27); M G > M C (ES = 0 14).

Posttest: O n isolated word test, M P > MG (ES = 2.12); M P > M C (ES = 3.43); M P > NM (ES = 4.50); M G > M C (ES = 1.28); M G > NM (ES = 1.52); M C > NM (ES = 0.41, p = ns). O n multiple choice test, M P > MG (ES = 1.93); M P > M C (ES = 3.19); M P > NM (ES = 3.19); MG > M C (ES = 0.78); MG > NM (ES = 1.16); M C = N M (ES = 0.00, p = m). Pre- to posttest changes significant for MP and MG only on isolated word and multiple choice tests.

Two-week follow-up: MP > N M on multiple choice delayed test (ES = 0.92) only. All other differences were ns. MP > MG (ES = 1.47); M P > M C (ES = 1.43); MG > M C (ES = 2.02); M G < N M (ES = -0.20); M C < N M (ES = - 0.79). Pre- to posttest changes significant for M P on isolated word delayed test only.

Transfer: O n sentence anomaly test, M P > M G (ES = 1.42); M P > M C (ES = 1.89); MP > NM (ES = 3.09); M G > M C (ES = 0.34, p = m); MG > NM (ES = 1.1 1, p = m); M C > NM (ES = 0.8 1, p = ns). O n sentence paraphrase test, MP > MG (ES = 1.50); MP > M C (ES = 2.78); M P > N M (ES = 1.52); MG > MC (ES = 2.44); MG > NM (ES = 0.18. p = ns); M C < N M (ES = - 1 . 4 4 , ~ =

us). Pre- to posttest changes significant for M P only on both tests.

TABLE I (Continued) Expt. 3 10 students with Within-subiects MP svnonvm 12- item each of Posttest: MP > N1 on isolated word (ES = 36.88) and multiple choice (ES =

LD (6 male, 4 design in which female); M age = students served as 10-12 years.; I Q their own = normal; controls. Median reading' = 2.7 grade; Voc. '= below grade level; Grade: 4

, , instruction (MP) vs. No-Instruction Control

isolated word. 12.60) vocabulary tests.

Follow-up: NA

Transfer: MP > N1 on sentence anomaly (ES = 10.10) & comp. items (ES = 1.96) tests. Differences between groups on story retell and Cloze were ns, MP > N1 (ES = 0.72) on story retell, and MP > N1 on Cloze (ES = 0.44)

multiple choice, sentence anomaly & paraphrase tests. 10- item factual passage comprehension questions. Cloze and story retell, tests.

2 to 4 days; 30 min each.

Schuster, Stevens, & Doak (1 990)

2 students with A multiple probe LD (1 male, 1 design across female); M age = students and 10.6 years.; 1Q = replicated across 89; Word sets of word reading' and definitions.

Constant time delay (CTD) procedure.

Word definition recall probes. Each probe included two word sets of 5 words each.

Posttest: CTD > baseline (PNDs = 92%).

6-, lo-, & 14-week follow-up: Maintenance > baseline (PNDs = 100%). Mean =13.5 sessions; 39 min. Transfer: Posttraining generalization M = 85% correct on both reading words

and providing the target word when given the definition. passage amp.'= 1 to 2 yrs. < grade level; Grade: 5

ScrugJp, Mastropieri, Bakken, & Brigham (1993)

26 students with LD (21 male, 5 female); M age = 14.4 years.; I Q = 84.92; Reading' & spelling' = 67.8 & 66.9; Grades: 7 & 8

Within-subjects crossover design. Classes stratified by grade & randomly assigned to 2 conditions; order of 2 treatments for 2 instr. units counterbalanced.

Activitylinquiry oriented (AI) method vs. textbook instruction (TI).

Recall tests that consisted of a free recall question followed by 24 questions that included 8 voc. production items, 8 factual recall items, and 8 application items.

Posttest: AI > TI on recall tests (ES 0.45).

1-wk follow-up: A1 > T I on delayed recall tests (ES = 0.48).

Transfer: NA 3 sessions, 3 consecutive days; 50 min each.

Veit, Scruggs, &

64 students with LD (45 male, 19 female); M age = NA; I Q = 92.5; Reading' = 3.8 grade (about 4 years below grade level); Grades: 6, 788

Two-group posttest only design. Students assigned to 24 small groups and groups randomly assigned to two instructional conditions.

Mnemonic (MN) instruction vs. direct questioning (Dl).

14-item voc. recall test of dinosaur word pans. 12- item voc. application test of dinosaurs' names. Delayed recall production and identification tests covered content from the 3 lesson tests.

Posttest: MN > Dl on loose scorine vocabulary test (ES = 0.82) and , . -, - - vocabulary application test (ES = 0.81). On the strict scoring vocabulary test, MN > Dl (ES = 0 . 5 5 , ~ = w). Mastropieiri

(1 986) 3 sessions; 3 lessons (one each on voc. related to dinosaur name pans, dinosaur attributes, & extinction of dinosaurs); 10 min each.

1 -day follow-up: MN > Dl on the recall production (ES = 1.4 1) and identification tests (ES = 2.07).

Transfer: NA

l i l t "yd tests developed by researchers and 2 inves- I i; itions (7%) used a standardized test.

Interventions were categorized as keyword or mnemonic strategies, cognitive strategies, direct instruction (Dl), activity-based method, constant 1 i me delay (CTD), and computer-assisted instruc- I ion (CAI). Table 1 provides descriptive informa- lion for each of the intervention studies.

Keyword or Mnemonic Strategies. Key- vs ord or mnemonic strategies involve two compo- nents, keyword and imagery links (Mastroprieri, kruggs, & Fulk, 1990). The keyword link pro- \ides a similar sounding familiar word to associate with the unknown vocabulary word. The imagery link provides a picture of the definition of the un- .nown word interacting with a picture of the key- word. T h e phonetic and visual imagery :omponents of the target word and its definition -.ewe to facilitate memorization and recall of tar- get vocabulary. Six studies were found that imple- mented a keyword mnemonic strategy to help students learn key vocabulary.

In a two-experiment study, Mastropieri, Scruggs, Levin, Gaffney, and McLoone (1985) compared the keyword strategy with a DI method on the recall of vocabulary definitions. Students in both experiments were stratified by grade level and randomly assigned to the two treatment con- ditions. Students in the mnemonic instruction condition were taught to use the keyword strat- egy. In the DI condition, students were taught using drill and practice procedures. While an in- teractive picture of the vocabulary word and word clue were presented in the mnemonic condition, students in the DI condition were provided with a picture of the vocabulary word. Students in both conditions were taught 16 low-frequency, unfamiliar English vocabulary words. In Experi- ment 1 , the instructor provided both the key- words and mnemonic pictures to 32 students with learning disabilities in Grades 7, 8, and 9, whereas in Experiment 2, 37 students with learn- ing disabilities in Grades 6, 7, and 8 had to self- generate the mnemonic imagery. Results indicated that students in the mnemonic instruc- tion condition outperformed students in the DI condition whether the instructor provided the

pictures (ES = 2.52) or students generated the im- agery (ES = 0.98).

Condus, Marshall, and Miller (1986) used a four group pretest-posttest design to investigate the differential effectiveness of an imposed key- word mnemonic strategy, a picture context strat- egy, a sentence-experience context strategy, and a control condition on the vocabulary acquisition and maintenance by children with learning dis- abilities. Thirty-two students with high-receptive vocabularies and 32 students with low-receptive vocabularies were randomly assigned to one of four conditions. A total of 50 vocabulary words grouped in sets of 10 were taught each week. In the keyword-image treatment, students learned word meanings using the following three steps: (a) learn keywords (phonetic link), (b) remember the content of black-and-white drawings (imagery link) that include a representation of the keyword interacting with the definition, and (c) recall the keyword and its picture when given the target word. In the picture-context condition, students learned word meanings using only the illustration representing the word definition. In the sentence- context condition, students listened to a teacher read a short passage containing the target word and answered a question designed to help them relate the meaning of the word to a personal expe- rience.

Results indicated that students in the key- word condition outscored students in all other conditions across four levels of time (immediate posttest following instruction, posttest following completion of each weekly test, 2 weeks mainte- nance test, and a test 8 weeks after maintenance testing) on multiple choice tests that assessed defi- nition recall. Mean scores of control students were significantly lower than all other conditions across time of testing. In addition, students with high-receptive vocabularies outperformed stu- dents with low-receptive vocabularies across all conditions. Further, students with low-receptive vocabularies in the keyword condition outper- formed students with high- and low-receptive vo- cabularies in the other conditions on the 8-week follow-up test. Findings from this study are en- couraging in that the keyword mnemonic strategy not only fostered students' vocabulary knowledge acquisition but also enhanced their recall perfor- mance over time.

* McLoone, Scruggs, Mastropieri, and

Zucker (1986) examined the effects of a keyword strategy and a directed rehearsal strategy on learn- ing 16 low-frequency English vocabulary words and 16 Italian vocabulary words. Sixty students with learning disabilities in Grades 7 and 8 were randomly assigned to either a mnemonic or a di- rected rehearsal condition. Students in both con- ditions were taught to not only use their assigned strategy when receiving teacher instruction, but also apply it independently (transfer). Students in the mnemonic condition were taught to generate their own keywords and interactive pictures dur- ing the transfer task, whereas students in the di- rect rehearsal condition were taught two steps (i.e., verbally state each word and definition) to apply the rehearsal strategy. Results indicated that both the mnemonic and directed rehearsal strate- gies were equally effective in teaching vocabulary to students with learning disabilities. However, students using the keyword strategy scored signifi- cantly higher than the direct rehearsal strategy group on recall (ES = 3.13) and transfer measures (ES = 2.98).

Veit, Scruggs, and Mastropieri (1986) com- pared the effectiveness of a mnemonic strategy and a direct questioning condition. Sixty-four students with learning disabilities in Grades 6, 7, and 8 were assigned to instructional groups, and groups were randomly assigned to either of two instructional conditions. Students in both the mnemonic and direct questioning conditions were taught three lessons related to word pans of dinosaur names, attributes of dinosaurs, and ex- tinction of dinosaurs. Results indicated that stu- dents in the mnemonic condition significantly outperformed students in the direct questioning condition on the vocabulary test using loose scor- ing ("scored as correct items for which any part of the correct response was given," p. 305; ES = 32) and vocabulary application test (exact response or close synonym scored as correct; ES = .8 1 ). Al- though students in the mnemonic condition scored higher than those in the direct question condition on the vocabulary test using strict scor- ing (only independent correct responses scored as correct), differences between groups were not sig- nificant. In addition, the mean score of students in the mnemonic group was significantly higher than that of the direct questioning group on both

production (ES = 1.4 1) and identification (ES = 2.07) recall tests that covered the content of all three lessons. Interestingly, this study demon- strated "the adaptability of mnemonic instruction to several aspects of a single content area" (p. 300).

In another study, Mastropieri, Scruggs, and Fulk (1990) taught 25 students with learning dis- abilities in Grades 6, 7, and 8 to learn a vocabu- lary list of concrete and abstract words. The authors stratified students by grade level and ran- domly assigned them to either a keyword mnemonic condition or a rehearsal condition. In the keyword condition, students were taught 16 vocabulary words using keywords and mnemonic pictures. The experimenter described the keyword and pictorial strategy for each word. Students in the rehearsal condition were taught the same vo- cabulary words using drill and practice only; they were not shown keywords or mnemonic pictures. The study indicated that keyword mnemonic in- struction resulted in higher levels of definition re- call (ES = 2.80) and comprehension (ES = 1.80) than the rehearsal method. Further, the effect for item type on the production test only was signifi- cant, favoring the mnemonic group on concrete words.

In sum, mnemonic or keyword approaches examined in six group design studies emphasized the importance of explicit phonetic and imagery links promoting definition recall of the target word. The investigations reported the superiority of the keyword approach over traditional drill and practice methods for improving vocabulary per- formance (mean ES = 1.93; SD = 1.03, n = 5). Maintenance effects in one study (Veit et al., 1986) was large (ES = 1.74). In addition, a large transfer effect (ES = 2.98) was seen in the study by McLoone et al. (1986).

Cognitive Strategy Instruction. Cognitive strategy instruction provides students with strate- gies and a framework for understanding a seman- tic network of words. Ten similar investigations by Bos and her colleagues provide support for uti- lizing interactive cognitive strategies to foster vo- cabulary learning by students with learning disabilities. Semantic Features Analysis (SFA), Se- mantic Mapping (SM), and SemanticISyntactic Feature Analysis (SSFA) are interactive cognitive strategies that are designed to help students cate-

gorize vocabulary words by noting similarities and Jifferences among related ideas (Bos & Anders, 1 990).

In the first study, Anders, Bos, and Filip ( 1984) compared the effectiveness of SPA and a traditional vocabulary look-up activity on con- cent-related vocabulary and reading comprehen- sion performance of 64 students with learning disabilities. Intact special education classes were randomly assigned to the treatment or control condition. Students in each class were also blocked for grade (freshmenlsophomores and j u- niorslseniors) and five instructors were randomly assigned to teach the two groups. Students in the vocabulary look-up condition were instructed to look up 10 "difficultn words in the dictionary and write a definition and sentence for each word. The remainder of the class time was used to read the given passage in preparation for the compre- hension test. Students in the SFA condition were taught to complete a relationship chart using a two-step process, in which the "major concepts presented in the passage were listed across the top and the related vocabulary was listed down the side" (p. 163). First, the instructor described the major concepts and each vocabulary word. Next, students were taught to rate each vocabulary word in relation to each major concept as having a pos- itive relationship, a negative relationship, unre- lated, or don't know the relationship. Instruction encouraged students to read the passage to verify their ratings and clarify any "don't know" rela- tionships. Results indicated that students in the SPA condition outperformed students in the look-up condition on both vocabulary (ES for vo- cabulary comprehension = 1.35; ES for vocabu- lary conceptualization = 1.52) and compre- hension (ES = 1.70) assessments.

In the second study. Bos, Anders, Filip, and Jaffe (1 989) compared the short-term and long- term effects of SFA and dictionary method (DM). Intact special education classes were randomly as- signed to the two conditions. Instruction in the SFA condition focused on discussing and com- pleting a relationship chart, activating prior knowledge, predicting relationships between new md old knowledge, and generating definitions of unknown words in a content area reading passage. Students in the DM condition used a dictionary EO define words and write a sentence for each

word. Results indicated that students in the SFA condition performed significantly better than stu- dents in the DM group on vocabulary (ES =

1.64) and conceptual items (ES = 1.63). Al- though there were no main effects for time or treatment by time, "students neither lost nor gained a significant amount of information from the time of initial test and administration to fol- low-up" (p. 388).

In the third study. Bos, Allen, and Scanlon (1989) worked with 42 elementary bilingual (EnglishISpanish) students with learning disabili- ties to investigate the differential effects of SM, SFA, SSFA, and DI on vocabulary knowledge ac- quisition and maintenance. Four instructors were randomly assigned to at least two different in- structional conditions. Instruction and assessment materials were developed in both English and Spanish. Students used their preferred language during instruction, passage reading, and the mul- tiple-choice test. Instruction in the DI group in- cluded techniques of oral recitation, positive and corrective feedback, and systematic review and practice of vocabulary and definitions to facilitate memorization of concise, context-related defini- tions. In contrast, students in the three interactive conditions were asked to predict vocabulary defi- nitions and to use prior knowledge to relate the new words to their own experiences. In addition, students in the SM condition discussed their pre- dicted meanings and constructed a map. The SFA condition students completed a relationship chart based on their predicted meanings. Students in the SSFA condition not only completed a rela- tionship chart, but also completed five cloze-type sentences using information from the chart. Re- sults indicated that students in the SSFA condi- tion scored significantly higher (ES = .49) than students in the DI condition on the vocabulary tests. However, no other comparisons were signif- icant. On the comprehension assessment, SM (ES = .87) and SPA (ES = 1.03) students scored significantly higher than those in the DI condi- tion. Although the written recall scores across conditions were significantly better at posttest than at follow-up on conceptual units or holistic scores, no significant differences among groups were noted.

In the fourth study, Bos and Anders (1 990) investigated the short-term and long-term effects

of DI, SM, SFA, and SSFA. Participants included 61 junior high school students with learning dis- abilities who were randomly assigned to one of the four intervention conditions and instructed in groups of 6 to 12 students. Results indicated that students in the SFA (ES = 1.06) and SM (ES = 1.25) conditions learned significantly more vocabulary words than students in the DI condi- tion at posttest. In addition, students in all three interactive instructional conditions outperformed students in the DI condition at follow-up (mean ES = 1.05). Although all three interactive groups scored significantly higher (mean ES = 1.35) than the DI group at posttest on the comprehension items, only students in the SSFA condition out- performed (ES = 1.44) DI students at follow-up. Neither short-term nor long-term learning showed significant differences across the three in- teractive groups for both vocabulary and compre- hension assessments.

Written recalls were analyzed for the rele- vant vocabulary generated, conceptual units, scriptural knowledge, and holistic rating. There were no significant differences among interactive groups on the written recall data. Maintenance findings (4 weeks postintervention) indicated that students in the SSFA (ES = 1.89) and SFA (ES = 1.42) conditions outperformed DI students on recalls analyzed for relevant vocabulary gener- ated. When recalls were analyzed for relevant, ac- curate conceptual units generated, only follow-up data indicated that SSFA (ES = 2.48) and SFA (ES = 1.83) students performed significantly bet- ter than DI students. All experimental groups demonstrated significantly higher quality scriptal knowledge than DI students at follow-up only (mean ES =1.40). Finally, students in the SFA (ES = 1.29) and SSFA (ES = 1.57) conditions generated significantly higher holistic ratings than students in the DI condition at follow-up only.

In the fifth study, Bos and Anders (1992) provided further support for interactive teaching strategies (SM, SFA, and SSFA). In a series of six experiments (three phases with two experiments in each phase), they worked with upper elemen- tary bilingual students with readingllearning dis- abilities (n = 42,47, and 26 in Phases 1, 2, and 3, respectively) studying social studies content and junior high students with readingllearning dis- abilities (n = 61, 53, and 22 in Phases 1, 2, and 3,

respectively) studying science content. In Phases 1 and 2 studies, students participated in one of the three interactive teaching strategies or in a com- parison condition of definition instruction. While researchers instructed students in Phase 1 studies. special education teachers delivered all instruction in Phase 2 studies. In Phase 3, special educators implemented the interactive learning strategies, SM and SFA, and students used them in coopera- tive groups.

Results for Phases 1 and 2 studies indicated that posttest and long-term effects for the interac- tive strategy conditions when compared to the de- finition instruction condition were substantial for both bilingual elementary (ES vocabulary score range = .50 to 1.28; ES comprehension score range = .81 to 1.46) and junior high students with learning disabilities (ES vocabulary score range = .83 to 1.0 1 ; ES comprehension score range = .78 to 1.55). In addition, comparisons between researchers and teachers indicated that effect sizes were similar. Results from Phase 3 in- dicated that bilingual elementary and junior high students with learning disabilities in both interac- tive conditions greatly increased their content knowledge from pre- to posttest (mean ES = 2.82. and 3.64 for bilingual elementary and junior high students, respectively), and the learning was maintained at a 1-month follow-up. Further, these students' performance was comparable to that of a normative comparison group of average achieving students at posttest (mean ES = 0.40 and 0.78 for bilingual elementary and junior high students) and follow-up (mean ES = 0.35 and 0.78 for bilingual elementary and junior high stu- dents).

In 'sum, the 10 group design cognitive strat- egy investigations reviewed incorporated instruc- tional features that emphasized categorizing vocabulary words by noting similarities and dif- ferences among related ideas using semantic maps and semantic feature analysis. Results indicated large effects for cognitive strategy instruction (mean ES = 1.10; SD = 0.39, n = 10). Specifically, interactive cognitive strategies (e.g., SFA, SSFA, SM) were found to be superior to traditional in- struction (e.g., dictionary method). Further, fol- low-up effects in seven studies were large (mean ES = 0.94; SD = 0.31) and transfer effects in two

St uc fll :

for rela real Sch voc prit ing voc tat He c ht wo thr atit we gal

in<

Fe( in; st1 m wt er ie st c< el S1

V,

tl ti ii

F <

t

I

1 1 I

studies were moderate (mean ES = 0.59; SO = 0.45).

Direct Instruction. Instructional techniques for promoting vocabulary learning presuppose a relationship between vocabulary knowledge and reading comprehension (Pany, Jenkins, & Schreck, 1982). It is hypothesized that if relevant vocabulary can be directly taught and learned prior to reading, then understanding of the mean- ing of the text will increase. Direct instruction of vocabulary includes an explicit, systematic presen- tation of a word and its meaning (Swanson, Hoskyn, & Lee, 1999). During DI, teachers check for student understanding of the target word, facilitate active participation by all students through teacher-guided applications, and system- atically transfer the responsibility of independent word learning to students. Two studies investi- gated the effects of DI with students with learn- ing disabilities.

Pany and Jenkins (1978) examined the ef- fects of three instructional strategies on the read- ing comprehension performance of 6 elementary students with learning disabilities. A repeated measures randomized block factorial design in which students served as their own controls was employed. The three instructional strategies var- ied with regard to the amount of DI provided. In- struction in the meanings from context (MC) condition provided no DI and placed the least emphasis on word meanings. It was assumed that students in this condition would acquire new word meanings from context dues in the stories they read. In the meanings given (MG) condi- tion, instruction focused on word meanings. The instructor provided students with the meanings of preselected words as they occurred in the story. Students in the meanings practiced (MP) condi- tion received the most DI. In this condition, the meanings of preselected words were presented and practiced via flash cards prior to reading the story. Results indicated that students in the MP condi- tion outperformed students in the MC (ES =

5.16) and MG conditions (ES = 4.30) on the im- mediate isolated vocabulary test. On the vocabu- l.iry in context test, students in the MP condition outperformed students in the MC (ES = 4.62) and MG conditions (ES = 3.61). In addition, dif- ferences in mean scores from pretest to posttest on the vocabulary in context test were significant

for the MP (ES = 4.01) and MG (ES = 1.52) con- ditions only. No significant treatment effects were found on the story comprehension factual recall test. Significant differences favoring the MP con- dition over the M C and MG conditions (ES = 3.65 and 2.89, respectively) were noted on the delayed (3 to 8 weeks later) isolated vocabu- lary test.

Pany, Jenkins, and Schrek (1982) provided further support for DI to promote vocabulary de- velopment. They employed the same instructional procedures as in their previous study to teach vo- cabulary meanings to 6 fourth- and fifth-grade students with learning disabilities (Experiment 2). The effects of the three instructional conditions were contrasted with the no-meanings condition, in which students simply read the target word printed on an index card. In Experiment 3, the authors worked with 10 fourth-grade students with learning disabilities to extend the research by exploring the effects of vocabulary instruction on both passage and sentence comprehension. Both experiments used a within-subjects design in which students served as their own controls.

Results for Experiment 2 indicated that the conditions requiring the most DI appeared to be the most effective for teaching synonyms. On the isolated word test, practice mean scores exceeded given (ES = 2.12), context (ES = 3.43), and con- trol means (ES = 4.50). Given mean scores, in turn, exceeded context (ES = 1.28) and control means (ES = 1.52). O n the multiple choice test, practice mean scores exceeded given (ES = 1.93). context (ES = 3-19), and control means (ES = 3.19). Given mean scores, in turn, exceeded context mean scores (ES = 1.52) only. Further, significant pretest to posttest differences were seen for practice and given groups only on isolated word and multiple choice tests.

Maintenance data indicated that students retained more vocabulary words during the prac- tice condition and significantly outscored those in the control condition (ES = 0.92) on the multiple choice delayed test. Further, significant pretest to posttest differences were seen for the practice group only on the isolated word delayed test. In- struction in the practice condition also led to the best sentence comprehension results. On both sentence anomaly and sentence paraphrase tests, practice means exceeded given (ESs = 1.42; 1 SO),

context (ESs = 1.89; 2.78) and control means (ESs = 3.09; 1 S2). Given mean score, in turn, ex- ceeded context mean score on the sentence para- phrase test (ES = 2.44) only. Significant pretest to posttest changes were found for practice group only on both sentence anomaly and paraphrase tests. Findings from Experiment 3 indicated that synonym practice was highly effective when com- pared to the no-synonym instruction condition for vocabulary teaching on isolated word (ES = 36.88) and multiple choice tests (ES =

12.60). Also, results indicated positive transfer to sentence anomaly (ES = .lo. 10) and passage com- prehension tests (ES = 1.96) for the synonym practice group only.

In sum, results of the effectiveness of DI ex- amined in three group design investigations indi- cated that as DI of word definitions increased, student performance on vocabulary measures im- proved (mean ES = 9.78; SD = 12.97, n = 3) and maintained over time (mean ES = 0.97; SD =

1.46; n = 2). Although DI did not result in trans- fer effects to story recall in the Pany and Jenkins (1978) study, the synonym training condition in the Pany et al. (1 982) study led to improved com- prehension transfer when compared to the con- trol conditions (mean ES = 1.49; SD = 1.60, n = 3).

Constant Time Delay (CTD). In CTD, an initial 0-s time delay is used in which the instruc- tor presents a vocabulary word and immediately states the definition. In subsequent trials, the in- structor presents the word, pauses for a fixed time period (3-5 s), and prompts the student for the correct definition. An incorrect response is fol- lowed by the instructor repeating the word and stating the correct definition. This technique re- sults in near error-free learning (Cast, Wolery, Morris, Doyle, & Meyer, 1990). Schuster, Stevens, and Doak (1990) used a multiple probe design across students and replicated across sets of word definitions to examine the effects of a 5-s CTD procedure to teach word definitions. Target words included two sets of five words each de- rived from the students' reading series. Instruc- tional sessions consisted of 30 trials, during which each set of five words was presented randomly six times. Results indicated improved posttest perfor- mance for the two students with learning disabili- ties (mean PND = 93%). Further, these students

achieved 100% accuracy after only three to four instructional sessions. Maintenance of correct rc- spending (PND = 100%) was evident up to 14 weeks after the training ended for both students, Generalization results indicated mean correct per- formance of 85% on reading words and providing the correct word when given the definition.

Activity-Based Methods. In this method, vo- cabulary is taught within the context of develop- mentally appropriate discipline-specific activities. Students engage in practical, concrete, hands-on learning as they interact with new vocabulary terms (Mastropieri & Scruggs, 1992; Rutherford & Algren, 1990). Scruggs, Mastropieri, Bakken, and Brigham (1993) studied the effects of an ac- tivity-based, inquiry-oriented approach versus a textbook approach on science learning with mid- dle school students with learning disabilities. A within-subject crossover design was employed in which all students received instruction under both conditions. Instruction in the activity-based condition required students to work on activities in small groups, whereas the textbook condition consisted of teacher presentation or textbook reading. Results indicated that activity-based in- struction, when appropriately structured, facili- tates content word knowledge of students with learning disabilities when compared to the text- book approach (ES = .45). Also, students taught with the activitylinquiry-oriented methods and materials scored higher than the textbook group on 1-week postinstruction maintenance tests (ES = 0.48).-In general, this study reported positive findings both in terms of immediate and long- term (1 week later) effects.

Computer Assisted Instruction (CAI). CAI is being used increasingly in classrooms to supple- ment teacher instruction, provide students with drill-and-practice on basic skills, and teach con- tent knowledge. CAI is an alternate way of learn- ing educational material that may be especially beneficial to students with disabilities. In a two- pilot study, Boettcher (1983) used a one group pretest-posttest design to investigate the effective- ness of a computer-based reading program, Read- ing Comprehension System (RCS), designed to provide diagnosis and practice in five comprehen- sion skills. Comprehension skills included (a) se- mantics (e.g., synonyms, antonyms, simple analogies); (b) syntax (e.g., word order, sentence

- $1 ~ I I C ture); (c) relationships (e.g., comparisons, re- l.it I, inships between words); (d) inferences (infor- in.inon implied, not explicitly stated, in text); and (r) interpretations (identifying main characters, d i n g factual generalizations based on story in- formation). Twenty-eight students with learning 1is.ibiIities in Grades 4 to 6 from two intact class- rooms participated in the first pilot study. Over a period of 9 weeks, the mean time using the com- p i e r program was 6.8 hr. Results indicated that the average gain for students was close to or over a yen on the vocabulary (M = + 1.32) and compre- hcnsion subtests ( M = + 1.58) of the California At hievement Test. The second pilot study tested the- RCS for an entire school year with 22 stu- Icnts with learning disabilities ages 7 to 13 years in a self-contained classroom. Student time on the computer over the 9 months of the study aver- ~ g e d 7.4. Results indicated no appreciable pretest to posttest gains (0.9 grade gain to 1.2 grade loss) o n the standardized test.

Horton, Lovitt, and Givens (1988) used a pretest-posttest design to examine the effective- ness of a computer-based vocabulary program to tcach geographical terms. Six students with learn- ing disabilities in ninth grade participated in computer sessions involving a pretest, practice, posttest sequence. Students received self-paced computerized vocabulary program instruction on v.irious word sets at individual workstations in the c imputer lab. Results indicated significant gains (rom pretest to posttests for students with learn- n g disabilities (mean ES = 2.22) on experimental icems only. Interestingly, performance of students I both groups improved over time (from Posttest 1 to Posttest 2 to Posttest 3) with CAI practice.

Hebert and Murdock (1994) used a single- ubject alternating treatments design to compare I he effectiveness of three output modes of CAI n o speech, synthesized speech, and digitized 'peech) in teaching vocabulary words to three stu- Jents with language-learning disabilities. The Word Attack Plus vocabulary program with defin- itions, contextual sentences, and multiple choice rests was used with all three output modes. In seneral, results indicated that students learned better with synthesized and digitized speech than :hey did without speech. Mean scores for synthe- 4zed and digitized speech conditions improved

over baseline (PND = 72% and 61%, respec- tively) for all three students in the study.

In contrast to the studies involving CAI programs, Johnson, Gersten, and Carnine (1987) examined the effects of the size of teaching sets on vocabulary learning of 25 high school students with learning disabilities. Students were matched by pretest scores and randomly assigned to one of two CAI vocabulary instruction conditions. Stu- dents in the small teaching set (STS) program condition received instruction and practice on small sets of words with cumulative review on previously learned words, whereas the large teach- ing set (LTS) program group received teaching and practice on words in sets of 25 with no cu- mulative review. Results indicated that signifi- cantly more students in the STS condition reached mastery within 1 1 sessions than students in the LTS condition (ES = -0.88). Training for both groups led to improved vocabulary learning and retention 2 weeks later. However, the STS group learned the material more efficiently (7.6 sessions) than the LTS group (9.1 sessions). Mean performance on the posttest was close to mastery for both STS and LTS groups, 84% to 87% correct, respectively. Of particular interest is that the mean posttest scores for students with learning disabilities ( M = 86%) were similar to those for their 10th-grade nondisabled peers (81 %). Generalization data indicated that stu- dents in both conditions performed poorly on measures requiring alternate response formats (open-ended oral test of word meanings and pas- sage comprehension).

Koury (1996) used a three-goup posttest- only design study to investigate the effects of preteaching new science vocabulary prior to using the content textbook with and without the use of video anchors. The study compared the perfor- mance of 123 fifth-grade students with and with- out learning disabilities on their knowledge of written science definitions as well as the effects of vocabulary instruction with extensive discussion with and without video anchors on knowledge of written science definitions. Video anchored in- struction in this study integrated the use of video clips with CAI to facilitate the connection be- tween prior knowledge and new vocabulary terms. Group I (all general education students) was pretaught science vocabulary using extensive

discussion without video anchors. Group I1 (all general education students) received the same in- struction as Group I, but with video anchors. Group I11 (all students with learning disabilities) received the same intervention as Group 11. Re- sults indicated that, while general education stu- dents in Groups I and I1 performed equally well, special education students in Group I11 per- formed significantly poorer than the general edu- cation students in Group I (ES = -2.02) and Group I1 (ES = -1.79) on the word knowledge test.

Overall, results of six CAI investigations that examined the effects of CAI programs, task variation, and video anchors on vocabulary learn- ing involving five group designs and one single subject design study indicated mixed effects (ES = 0.16, SD = 2.92, n = 2). Although positive effects were seen for CAI in four investigations, outcomes for use of integrated media (e.g., video anchors) and extended use of CAI (i.e., 9 months) for students with learning disabilities were limited.

D I S C U S S I O N

Overall, the studies reviewed suggest that vocabu- lary instruction for students with learning disabil- ities can lead to gains in word knowledge. Effect sizes calculated for 21 of the 27 investigations in- dicated large effects for the reviewed instructional techniques with the exception of the activity- based method (ES = 0.45, n = 1) and CAI (ES = 0.16,I > SD = 2.92, n = 2). Accepted inter- pretations for effect sizes with absolute values of .80 or greater are considered large effects, at or near .60 is considered a moderate effect, and .20 is considered a small effect (Cohen, 1988). How- ever, the unusually large positive effect sizes re- ported for the Pany et al. (1982) study deserve further comment. The effect sizes observed for synonym practice when compared to no synonym instruction on isolated word posttest, multiple choice posttest, and transfer test were 36.88, 12.60, and 10.10, respectively. These large effect sizes reflect the study's use of a no-treatment con- trol group and, therefore, an unweighted compar- ison between the experimental and comparison conditions. Further, the large negative effect size from the Koury (1996) study favoring the com-

parison group accounts for the large variance in the CAI studies. Also, this effect might be ex- plained by the use of a comparison group of gen- eral education students rather than students with learning disabilities. At the same time, the rela- tively small to moderate to large effect sizes re- ported for Experiments 5 and 6 of the Bos and Anders (1992) study should be interpreted with caution. These experiments included average achievers as a comparison group, who were not provided with the strategy instruction. In con- trast, the treatment group of students with learn- ing disabilities received cognitive strategy instruction. Differences in achievement levels and exposure to instruction make it difficult to inter- pret these results. As such, subsequent discussion is based on interpretation of mean effect size re- sults following removal of the outlier studies (Koury, 1996; Pany et al., 1982) with unusually large positive and negative effect sizes.

Specifically, results of intervention studies indicated that mnemonic approaches, cognitive strategy instruction, DI, activity-based method, and CAI appear to enhance vocabulary develop- ment for students with learning disabilities (mean ES = 1.47; SD = 0.80; n = 19). CTD was exam- ined in one single-subject design study, with posi- tive effects reported for the 2 students with learning disabilities. The effectiveness of these varied instructional approaches supports the gen- eral guidelines for context and explicit instruc- tion, as well as the need for a productive approach to word learning, (e.g., Baumann & Kame'enui, 1991; Stahl & Shell, 1999). Most investigations used researcher-designed vocabulary outcome measures and reported large effect sizes that are consistent with the findings of previous meta- analyses, which indicate large effects on nonstan- dardized measures (Elbaum, Vaughn, Hughes, & Moody, 1999; Swanson, Hoskyn, & Lee, 1999). Most of the reviewed studies involved comparison conditions, and vocabulary instructional tech- niques were found to be generally more effective than some traditional methods (e.g., dictionary method) and less direct approaches to vocabulary learning.

In addition to effective outcomes on posttests, scores on follow-up tests (mean ES = 0.98; SD = 0.62, n = 11) and transfer tests (mean ES = 1.44; SD = 1.35, n = 4) were also as-

I

, , , I .ired with large effect sizes. However, the ma- (Baker, Simmons, & Kame'enui, 1998; Biemiller, # , I 1 1 \ of the studies reviewed in this synthesis did 2001; Hart & Risley, 1995). As such, the need for I include an instructional emphasis on "deep additional research with young children is war- -

p m essing" at the generation level of understand- ranted. ~ I I F rhat is, depth of word learning was not gen- When treatment intensity was examined, i l i ~ e d , and maintenance of such word learning effects were largest for studies that provided less . r i rarely assessed. Whether vocabulary instruc- than 60 min of instruction (mean ES = 1.91; I ~ I I leads to student gains in comprehension (i.e., SD = 0.93, n = 6). Effective outcomes were also tli-l>[h of word knowledge and comprehension of noted for interventions that ranged in duration I ~ ~ X I ) is less clear given the limited number of from 60 to 150 min (mean ES = 1-34; SD = 1-25, mniies that assessed comprehension skills. Vocab- n = 2) or provided more than 150 min (mean I iy development requires different levels of ES 1.19; SD. 0.39, n = 6) of imtruction. This w ' ~ knowledge- As Beck and McKeown (19g1) finding that effective outcomes can be achieved 9 ¥knowin a word is not an all-or-nothing with re]atively short duration of vocabulary in- r1)position; it is not the case that one either struction is encouraging. M~~~ treatments were knows Or does know a (P. 79l). For ex- implemented, and the effects were l l l k when is a word truly known by a student? higher when implemented by researchers (mean 1 '1) students know a word if they recognize the ES = 1 -44; SD = 0.8 1, n = 13) than by teachers . . i n ing from a set of given choices or when they (mean Es = .05; SD , 0,44, = 5). p ~ ~ d u c e the word's definition? Should students be the effect size was largest for computers .ihle to state detailed definitions and know multi- (ES = 2.22), it was based on only one investiga- pic meanings of words (Carlisle, 1993)? Students tion. This finding is wi,, prwious re- v i ~ h learning disabilities often struggle to general- search that researcher-implemented treatments are i/e newly introduced vocabulary to novel situa-

generally associated with greater effects than litins if their original exposure to target words is

teacher-implemented treatments (Swanson et al., uperficial and not reinforced over time. There-

1999). However, the large effects associated with tore, it may be necessary to specifically teach gen-

teacher implementation suggest that providing ri.ilization to novel situations. Given the

teacher training on effective vocabulary interven- iportance of depth of word knowledge, future

tions can be beneficial. Although few studies re- research should consider vocabulary instruction ..

i d assessment, with an emphasis on association, ported the setting in which instruction occurred,

1 Jmprehension, and generation levels of word un- effect sizes were large whether instruction oc-

tierstanding (Baumann & Kame'enui, 199 1; curred in special education classrooms (mean

$1-ihl, 1986). ES = 2.30, SD = 0.71, n = 2), content area classes

With regard to the effectiveness of vocabu- (mean ES = 1.44, SD = 0.90, n = 3), or quiet

i r y instruction across grades, results indicated ef- rooms (ES = 1.93, SD = 0.83, n = 3).

tctive outcomes for elementary (mean ES = 1.31; In addition, students were instructed in

$/-J = 0.89, = 6), junior high (mean ES = 1-48: groups in the majority of studies reviewed (mean

= 0.87, = lo), and high school students Es = 1-02; SD = 0.41, n = 12)- However, the ef-

(mean ES = 1.79; SD = 0.37, n = 3). However, al- feet sizes for individual instruction (mean

~ l ~ ~ ~ ~ h most interventions are effective for stu- ES = 2.33; SD = 0.74, n = 6) and instruction in

t!cnts in Grades 4 through 12, benefits, of pairs (ES = 1.80, n = 1) were the largest. Given

:nage comprehension and vocabulary knowledge abilities in general education classrooms, it is - ! r e evident well before children enter school important that future research address the applic- I !-[art & Risley, 1995). These differences grow ability of these interventions within the context of

ider over time, and are difficult, if not impossi- peer tutoring to reinforce strategy use (Elbaum et !e, to ameliorate after they reach a certain point al., 1999; Fuchs & Fuchs, 1998).

*

Despite the positive effects of vocabulary instruction for students with disabilities, it must be noted that our search yielding the 27 investiga- tions on which this review was based is limited in nature. Few studies were available to support the effectiveness of the various interventions de- scribed. Given the recent attention to the impor- tance of vocabulary development in compre- hension (National Research Council, 1998; Snow, 2002), it is discouraging to observe the paucity of research on vocabulary instruction for students with learning disabilities in recent years. To be in- cluded in our review, we searched for studies from 1978 to 2002. With the exception of one study in 1978, all studies reported in our review were pub- lished between 1982 and 1996. Further, the same research team conducted a large proportion of these studies. Of the 26 investigations, Bos and colleagues and Mastropieri and colleagues con- ducted 10 and 6 investigations, respectively. In addition, the use of CAI when compared to tradi- tional and alternative methods of vocabulary in- struction is not known from the studies reviewed.

I M P L I C A T I O N S FOR P R A C T I C E

The findings of this review on vocabulary indicate several instructional implications for promoting word knowledge. The most obvious is that educa- tional researchers and practitioners must empha- size instructional methods that directly teach vocabulary. Results from this review suggest that there are effective and efficient research-based methods to choose from when selecting a particu- lar instructional approach for an individual stu- dent. Additionally, different approaches to vocabulary learning depend on different instruc- tional goals (Beck & McKeown, 199 1 ; McKeown & Beck, 1988). For example, if the purpose of in- struction is to introduce students to a new word and its definition, a DI approach might be used. If an instructional goal includes the expressive use of target vocabulary when making new associa- tions, a semantic instructional approach might be appropriate. Another implication is that practice is critical to vocabulary acquisition that, in turn, may lead to maintenance and generalization. Based on their research, Pany et al. (1982) found that vocabulary learning was maximized with practice. Given the importance of practice, re-

searchers and practitioners must work toward dc- veloping learning environments in which ade- quate time is devoted to judicious use and strategic application of newly learned vocabulary knowledge to comprehend text.

In addition, selecting effective CAI pro- grams that serve as potentially valuable aids in supplementing teacher instruction is critical. While CAI generally has led to improved vocabu- lary knowledge and may be an efficient and effec- tive instructional method (e.g., Johnson, Gersten, & Carnine, 1987), the practicality of CAI inter- ventions must be considered. Access to comput- ers, cost of software, teacher knowledge of effective software programs, time involved to in- struct (e.g., keyboarding skills) and manage stu- dent behavior are variables that may impact the potential effectiveness of CAI interventions. Often, the only difference between CAI and teacher instruction is that CAI is presented on a computer screen and may involve the presenta- tion of worksheet-type activities for the purpose of drill and practice rather than systematic strat- egy instruction. Thus, more research in the area of CAI related to vocabulary acquisition is needed to determine the possible benefits of this form of instruction for students with learning disabilities.

In summary, when considering the diffi- culty students with learning disabilities have with acquiring words from independent reading, inves- tigating the effects of vocabulary instruction seems paramount. Although positive effects have been observed for various vocabulary instruc- tional approaches for students with learning dis- abilities, future research should explore not only acquisition and maintenance of word knowledge, but also depth of processing and generalized word learning. In addition, it is important to consider practical classroom realities and resources, the ef- fectiveness and intensity of treatment for different age-grade groups and in different settings, in- structional arrangements, and the use of standard- ized outcome measures of treatment effectiveness.

R E F E R E N C E S

Adams, M. J. ( 1 990). Beginning to read: Thinking and learning aboutprint. Cambridge, MA: The MIT Press.

Anders. I? L., Bos. C. S., & Filip, D. (1984). The effect of semantic feature analysis on the reading comprehension of

!CJ

1-1

l i l t

1111

\r

In I E ti

B; Vi &

lit

Nf

B VI

c tt

h

E c

^ 1

I

I 1

I

a

1 1 :-disabled students. In J. S. Niles and L. A. Harris I. Changing Perspectives on ReadingLanguage Process-

' Instruction (pp. 162-1 66). Rochester, NY: The Na- I I heading Conference.

1 on, R. C., & Nagy, W. E. (1991). Word meanings. 1 '.am, M. L. Kamil, l? B. Mosenthal, & l? D. Pearson

I Handbook of reading research (Vol. 2, pp. 690-724). i l l - .lie, NJ: Lawrence Erlbaum.

11,. S. K., Simmons, D. C., & Kame'enui, E. J. (1998). . ulary acquisition: Research bases. In D. C. Simmons

. I 1. Kame'enui (Eds.), What reading research tells us . children with diverse learning needs (pp. 1 83-2 18).

I 1.11 ah, NJ: Lawrence Erlbaum.

I :ann, J. F., & Kame'enui, E. J. (1991). Research on d a r y instruction: Ode to Voltaire. In J. Flood, J. J.

I ipp, & J. R. Squire (Eds.), Handbook of research on

ing the English language arts (pp. 604-632). New York: I nillan.

1 . , I., & McKeown, M. G. (1991). Conditions of vo- I lary acquisition. In R. Barr, M. L. Kamil, P. B.

Mi a tha l , & l? D. Pearson (Eds.), Handbook of reading t rch (Vol. 2, pp. 789-814). Hillsdale, NJ: Lawrence

I I ' mm.

IL cer, B. J. (1988). Synthesizing standardized mean- . I lge measures. British Journal of Mathematical Psychol- . 41, 257-278.

1, ker, W. C. (1977). Teaching reading and language to I disadvantaged: What we have learned from field re- st. ch. Harvard Educational Review, 47, 5 18-543.

I{ miller, A. (2001). Teaching vocabulary: Early, direct, I 1 sequential. American Educator, 25(1), 24-28, 47.

I{ -richer, J. V. (1 983). Computer-based education: Class- I lm application and benefits for the learning-disabled 1 dent. Annals of Dyslexia. 33, 203-21 9.

I s, C. S., Allen, A. A., & Scanlon, D. J. (1989). Vocabu- I / instruction and reading comprehension with bilingual I rning disabled students. National Reading Conference

trbook, -38, 1 73- 179.

I i, C. S., & Anders, l? I-. (1990). Effects of interactive cabulary instruction on the vocabulary learning and

1 iding comprehension of junior-high learning disabled idents. /-earning Disability Quarterly, 13, 3 1-42.

1 IS, C. S., & Anders, P. I.. (1992). Using interactive iching and learning strategies to promote text compre- nsion and content learning for students with learning sabil i ties. Internationalfomal of Di.rabi/ity, Development,

. id Education, .59(3), 225-238.

is, C. S., Anders, I? L., Filip, D., & Jaffe, L. E. (1989). he effects of an interactive instructional strategy for en- incing reading comprehension and content area learning

for students with learning disabilities. Journal of Learning Disabilities, 22(6), 384-390.

Carlisle, J. (1993). Selecting approaches to vocabulary in- struction for the reading disabled. Learning Disabilities Re- search fir Practice, 8(2), 97-105.

Cohen, J. (1 988). Statistical power analysis for the behav- ioralsciences (2nd ed.). New York: Academic Press.

Condus, M. M., Marshall, K. J., & Miller, S. R. (1986). Effects of the keyword mnemonic strategy on vocabulary acquisition and maintenance by learning disabled children. Journal of Learning Disabilities, Im), 609-61 3.

Cunningham, A. E.. & Stanovich, K E. (1998). What read- ing does for the mind. American Educator, 22(1 & 2), 8- 1 5.

Elbaum, B. E., Vaughn, S., Hughes, M. T, & Moody, S. W. (1999). Grouping practices and reading outcomes for stu- dents with disabilities. Exceptional Children, 65,399-415.

Fuchs, L. S., & Fuchs, D. (1998). Researchers and teachers working together to adapt instruction for diverse learners. Learning Disabilities Research fir Practice, 13(3), 126-1 37.

Cast, D. L., Wolery, M., Morris, L. L., Doyle, I? M., & Meyer, L. L. (1990). Teaching sight word reading in a group instructional arrangement using constant time delay. Exceptionalig 1. 8 1-96.

Hart, B., & Risky, T R. (1995). Meaningfuldzfferences in the everyday experiences of young American children. Balti- more: Paul H. Brookes.

Heben, B. M., & Murdock, J. Y. (1994). Comparing three computer-aided instruction output modes to teach vocab- ulary words to students with learning disabilities. Learning Disabilities Research 6- Practice, 9(3), 1 36- 1 4 1.

Horton, S. V., Lovitt, T. C., & Givens, A. (1988). A com- puter-based vocabulary program for three categories of stu- dent. British Journal of Educational Technology, 19(2), 131-143.

Johnson, G., Gersten, R., & Carnine, D. (1987). Effects of instructional design variables on vocabulary acquisition of learning disabilities students: A study of computer-as- sisted instruction. Journal of Learning Disabilities, 20(4), 206-2 13.

Keel, M. C., Slaton, I). B., & Blackhurst, A. E. (2001). Acquisition of content area vocabulary for students with learning disabilities. Edu(Â¥at/o and Treatment of Children, 24(1), 46-71.

Koury, K. A. (1996). 'I'hc impact of preteaching science content vocabulary using integrated media for knowledge acquisition in ;I collaborative classroom. Journal of Com- puting in Childhood Edttcation, 7(3/4), 179- 197.

I.ipsey, M. W., & Wilson, D. B. (1993). The efficacy of psychological, educational, and behavioral treatment. American Psychologist, 48, 1 18 1 - 1209.

9

Mastropieri, M., & Scruggs, T. E. (1 992). Science for stu- dents with disabilities: A review of research. Review of Edu- cational Research. 62,377-4 1 1.

Mastropieri, M., Scruggs, T. E., & Fulk, B. J. M. (1990). Teaching abstract vocabulary with the keyword method: Effects on recall and comprehension. Journal of Learning Disabilities, 23(2), 92-96.

Mastropieri, M. A., Scruggs, T. E., Levin, J, R., GafFney J., & McLoone, B. (1985). Mnemonic vocabulary instruc- tion for learning disabled students. Learning Disability Quarterly. 8, 57-63.

McKeown, M. G., & Beck, I. L. (1988). Learning vocabu- lary: Different ways for different goals. Remedial and Spe- cial Education, 9(1), 42-52.

McLoone, B. B., Scruggs, T. E., Mastropieri, M. A., & Zucker, S. F. (1986). Memory strategy instruction and training with learning disabled adolescents. Learning Dis- abilities Research, 2(1), 45-53.

Murawski, W. W., & Swanson, H. L. (2001). A meta- analysis of co-teaching research: Where are the data? Rcme- dial and Special Education, 22,258-267.

National Reading Panel (2000). Teaching children to read: An evidence-based assessment of the scientific research litera- tun on reading and its implications for reading instruction: Reports of the subgroups. Bethesda, MD: National Institute of Child Health and Human Development.

National Research Council. (1998). Preventing reading dif- ficulties in young children. Washington, DC: National Academy Press.

Pany, D., & Jenkins, J. R. (1978). Learning word mean- ings: A comparison of instructional procedures. Learning Disability Quarterly 1.2 1-32.

Pany, D., Jenkins, J. R, & Schreck, J. (1982). Vocabulary instruction: Effects on word knowledge and reading com- prehension. Learning Disability Quarterly- 5, 202-215.

Reyes, E. I., Duran, G. Z., & Bos, C. S. (1989). Language as a resource for mediating comprehension. Yearbook of the National Reading Conference, 38,253-259.

Rutherford, F. J., & Algren, A. (1990). Science for all Americans. New York: Oxford University Press.

Schuster, J. W., Stevens, K. B., & Doak, l? K. (1990). Using constant time delay to teach word definitions. The Journal of Special Education. 24(3), 306-3 18.

Scruggs, T. E.. Mastropieri, M. A,, Bakken, J. P., & Brigham, F. J. (1993). Reading versus doing: The relative effects of textbook-based and inquiry-oriented approaches to science learning in special education classrooms. The Journal of Special Education, 27(1), 1 - 1 5.

Snow, C. E. (2002). Reading for understanding. Toward an R&D program in reading comprehension. Santa Monica, CA: RAND.

Stahl, S. A. (1986). Three principles of vocabulary instruc- tion. Journal of Readins 270,662-668.

Stahl, S. A., & Fairbanks, M. M. (1986). The effects ofvo- cabulary instruction: A model-based meta-analysis. Review of Educational Research, 56( I ), 72- 1 10.

Stahl, S. A., & Shiel, T. G. (1999). Teaching meaning w- cabulary: Productive approaches for poor readers. Read all about it! Readings to inform the profession. Sacramento: Cal- ifornia State Board of Education.

Stanovich, K. E. (1 986). Cognitive processes and the read- ing problems of learning-disabled children: Evaluating the assumption of specificity. In J. K. Torgesen & B. Y. L. Wong (Eds.), Psychologikal and educational perspectives on LD (pp. 87-131). Orlando, FL: Academic Press.

Swanson, H. L. (1986). Do semantic memory deficiencies underlie learning readers' encoding processes? Journal of Exceptional Child Psycholosy- 41.461 -488.

Swanson, H. L, Hoskyn, M., & Lee, C. (1999). Interventions for students with Itaming disabilities, New Yolk: Guilford.

Woodward, J., Carnine, D., & Collins, M. (1988). Clos- ing the performance gap: CAI and secondary education for the mildly handicapped. Journal of Educational Computing Research, 4(3), 265-286.

Veit, D. T, Scruggs, T. E., & Mastropieri, M. A. (1986). Extended mnemonic instruction with learning disabled stu- dents. Journal ofEducationa1 Psychology, 75(4), 300-308.

A B O U T T H E A U T H O R S

ASHA K. J ITENDRA (CEC #905), Professor and Coordinator of Speical Education ; LANA L. EDWARDS, Assistant Professor of Special Educa- tion; GABRIELL SACKS, doctoral candidate in special education, Department of Education and Human Services, Lehigh University, Pennsylvania. LISA A. JACOBSON, School Psychologist, Schuylkill Valley School District, Berks County, Leesport, Pennsylvania.

Correspondence concerning this article should be addressed to Asha K. Jitendra, Lehigh University, Department of Education and Human Services, Mountaintop Campus, 11 1 Research Drive, Bethlehem, PA 180 15-4794. E-mail: akj2@lehigh.edu Manuscript received October 2002; accepted April 2003.

J< G

JC In.

St

A I

re.

(1

Ye' 7)

ex. te?