Operational Definitions and Learning Disabilities || Operational Definitions and Learning Disabilities: An Overview

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<ul><li><p>Hammill Institute on Disabilities</p><p>Operational Definitions and Learning Disabilities: An OverviewAuthor(s): H. Lee SwansonSource: Learning Disability Quarterly, Vol. 14, No. 4, Operational Definitions and LearningDisabilities (Autumn, 1991), pp. 242-254Published by: Sage Publications, Inc.Stable URL: http://www.jstor.org/stable/1510661 .Accessed: 16/06/2014 15:00</p><p>Your use of the JSTOR archive indicates your acceptance of the Terms &amp; Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp</p><p> .JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact support@jstor.org.</p><p> .</p><p>Sage Publications, Inc. and Hammill Institute on Disabilities are collaborating with JSTOR to digitize,preserve and extend access to Learning Disability Quarterly.</p><p>http://www.jstor.org </p><p>This content downloaded from 62.122.77.28 on Mon, 16 Jun 2014 15:00:14 PMAll use subject to JSTOR Terms and Conditions</p><p>http://www.jstor.org/action/showPublisher?publisherCode=sagehttp://www.jstor.org/stable/1510661?origin=JSTOR-pdfhttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsp</p></li><li><p>OPERATIONAL DEFINITIONS AND LEARNING DISABILITIES: AN OVERVIEW </p><p>H. Lee Swanson </p><p>In 1981, the National Joint Committee for Learning Disabilities (NJCLD) adopted the fol- lowing definition: </p><p>Learning disabilities is a generic term that re- fers to a heterogeneous group of disorders manifested by significant difficulties in the ac- quisition and use of listening, speaking, read- ing, writing, reasoning, or mathematical abili- ties. These disorders are intrinsic to the in- dividual and are presumed to be due to central nervous system dysfunction. Even though a learning disability may occur concomitantly with other handicapping conditions (e.g., sen- sory impairment, mental retardation, social, or emotional disturbance) or environmental influ- ences (e.g., cultural differences, insufficient/in- appropriate instruction, psychogenic factors), it is not the direct result of these conditions or influences. (Hammill, Leigh, McNutt, &amp; Lar- sen, 1981, p. 336) This definition has been evaluated positively </p><p>compared to others (e.g., Interagency Commit- tee on Learning Disabilities, 1987; U.S.O.E., 1977; e.g., see Hammill, 1990; Silver, 1988). However, it is not an operational definition, be- cause it does not specify the operations or pro- cedures by which the construct of learning dis- abilities can be recognized and measured. For example, it is unlikely that current studies on learning disabilities would be published in refer- eed research journals if their subject sample de- scription relied solely on the NJCLD definition. Therefore, if we are to enhance our understand- ing of learning disabilities, serious consideration must be given to the selection of parameters that go into an operational definition. It is in this spirit that this special issue of the Learning Dis- ability Quarterly was developed. </p><p>In this opening discussion, I seek to distill some ideas that unify what otherwise might ap- pear to be a collection of unintegrated articles. The reader should remember, however, that each article is written from the authors' own research perspective. I deliberately solicited articles of di- </p><p>verse research perspectives to allow a number of issues to be considered. For example, in the first article Kavale, Forness, and Lorsbach discuss the limitations of operational definitions, whereas the article by Stanovich focuses on the irrelevancy of IQ. Likewise, Hynd, Marshall, and Gonzalez emphasize the relevance of studies originating from neuropsychology, Reynolds' ar- ticle targets psychometric models, while Bryan considers primarily social cognition. No doubt, to integrate these diverse perspectives will be no small feat. The purpose of this special issue, however, is not to show or seek unanimity among the contributors on how to operational- ize learning disabilities. Rather, the focus is on the commonality of conceptual issues that emerges in our attempts to operationalize learn- ing disabilities. </p><p>OPERATIONALIZING LEARNING DISABILITIES </p><p>Before reviewing each article in more detail, I will outline what I think are some fundamental points when one attempts to operationalize the term learning disabilities (LD). Three points are considered: selection of indicators, function of indicators, and parsimony. Selection of Indicators </p><p>The ultimate goal behind operationalizing the term learning disabilities is to enhance our abil- ity to replicate and generalize research findings to other samples with similar characteristics. Therefore, an obvious step in this process is for the researcher to specify the parameters or indi- cators used to determine a learning disability. That is, for each person with learning disabilities studied, a number is assigned that represents whether an indicator is present or absent, or </p><p>H. LEE SWANSON, Ph.D., Editor of the Learning Disability Quarterly, is Professor, School of Education, University of California- Riverside. </p><p>242 Learning Disability Quarterly </p><p>This content downloaded from 62.122.77.28 on Mon, 16 Jun 2014 15:00:14 PMAll use subject to JSTOR Terms and Conditions</p><p>http://www.jstor.org/page/info/about/policies/terms.jsp</p></li><li><p>"how much" of the indicator the person pos- sesses. Because learning disabilities cannot al- ways be defined directly (you might not know one when you see one), children with learning disabilities are usually separated from a general population on an array of indicators (see Hall &amp; Humphreys, 1982; Wong, 1985; for a discus- sion on this issue). Traditional indicators for sam- ple selection include descriptive statistics from standardized intelligence, achievement and pro- cess measures, as well as the sample's age, grade level, gender, ethnicity, length of time in special education, and socioeconomic status (however, see Keogh, 1986b). Additional indica- tors are sometimes given to the study's setting and methodological characteristics. </p><p>These indicators must be selected with care. For example, merely reporting means and stan- dard deviations from standardized tests does not allow easy replication due to the difficulty of gathering another sample with the same average characteristics. Instead, to enhance replication, researchers must provide specific details on how the subjects were selected and what types of sub- jects were excluded. If control subjects are used, they also need to be detailed in the same specific manner. </p><p>For example, problems may emerge when cut- off scores on certain measures are used in the sample selection process (e.g., Fletcher, Espy, Francis, Davidson, Rourke, &amp; Shaywitz, 1989). Although cut-off scores refine sample character- istics, they may introduce other constructs than the one intended by the researcher in framing the hypotheses. A cut-off score below the 25th percentile on a reading test, for example, may indicate an underlying construct of poor and/or nonsystematic instruction, rather than an inher- ent disability in mental processing (a fundamen- tal assumption of the learning disability construct; e.g., see Stanovich, 1986a, 1986b; Swanson, 1988). Thus, it is important to remember that indicators of learning disabilities may not be as exact as desired. Their selection involves both in- telligent decision making and construct valida- tion. However, this decision-making process is muddled by two factors: variations in sample se- lection and strategies for isolating processes. </p><p>Variations in parameter selection. A ca- sual review of the literature suggests the exis- tence of a wide array of parameters in opera- tionalizing the term learning disabilities (see </p><p>Keogh, 1983, 1988, 1990, for a review). For example, some students classified as learning disabled do not monitor their learning well (Borkowski, Estrada, Milstead, &amp; Hale, 1989; Wong, 1991), cannot generate phonological codes effectively when processing visual infor- mation (Siegel &amp; Ryan, 1988, 1989a, 1989b; Shankweiler &amp; Crain, 1986), demonstrate poor metacognitive skills (Palincsar &amp; Brown, 1987; Paris &amp; Oka, 1989), and cannot negotiate social situations well (see Bryan, for a review, 1991). </p><p>Thus, depending on one's research interest, one might operationalize a student with learning disabilities as being unable (a) to think logically or symbolically, (b) to access a language system adequately, (b) to exhibit adaptive social behav- iors, and so on. This wide variation in the selec- tion of indicators makes it difficult to integrate findings, as well as to establish a common core of variables in sample selection (Frankenberger &amp; Harper, 1987; Keogh, 1983, 1987; Shep- ard, Smith, &amp; Vojir, 1983). </p><p>At this point, there appears to be little con- sensus in the field of learning disabilities on the directions one should go in operationalizing learning disabilities. This lack of direction is best captured by reviewing Alice's dilemma in Won- derland: "'Would you tell, me please, which way I ought to go from here?' said the Cat. 'I don't much care where-'said Alice. 'Then it doesn't matter which way you go,' said the Cat. 'So long as I get somewhere,' Alice added as an ex- planation. 'Oh, you're sure to do that' said the Cat, 'If you walk long enough"' (Carroll, 1916, p. 60). </p><p>Isolating operations. Given the diversity in possible directions for operationalizing learning disabilities, a strategy is needed for identifying a common set of indicators. One obvious strategy would be to combine several relevant dimen- sions of learning disabled children's adaptive and nonadaptive behavior (for example, classroom functioning) into an overall index or set of marker variables. Such an index would draw upon replicated findings across an array of re- search designs and measures. Although such a checklist or set of marker variables would be un- wieldy due to the number of items selected, in principle, at least, it might provide a common device for researchers to use in separating chil- dren with and without learning disabilities. </p><p>Of course, this ideal tool is unattainable since </p><p>Volume 14, Fall 1991 243 </p><p>This content downloaded from 62.122.77.28 on Mon, 16 Jun 2014 15:00:14 PMAll use subject to JSTOR Terms and Conditions</p><p>http://www.jstor.org/page/info/about/policies/terms.jsp</p></li><li><p>many of the relevant dimensions of learning dis- abled children's functioning, such as poor strat- egy use (e.g., Palincsar, Brown, &amp; Campione, 1991), metacognitive deficiencies (e.g., Wong, 1991), or phonological awareness (e.g., Shank- weiler &amp; Crain, 1986), are not standardized or even identified. Further, the learning disabled child's poor adapting characteristics would have to include not only measures of vocabulary, so- cial judgment, and general information, but also </p><p>flexibility of thinking, responsiveness to system- atic instruction, generalization of skills to various tasks, compensatory skills used within and out- side the classroom, and so on. These latter char- acteristics exhibit themselves only in unique situ- ations and others cannot be evaluated except by observing this child over an extended period. Thus, again, the researcher is left seemingly with unlimited possibilities in terms of operational definition. The selection process is further exac- erbated because of the lack of an accepted the- ory within the field (e.g., Swanson, 1988, also see commentaries), as well as political policies that ignore scientific data in the assessment of such children (e.g., see Adelman &amp; Taylor, 1991; Chalfant, 1989; Keogh, 1986a, for re- view). </p><p>A more realistic strategy involves placing some constraints on these parameters by focusing on isolated operations, thereby operationalizing a learning disability in terms of a narrowly re- stricted range of operations. One example of an operational definition is outlined in an excellent chapter by Morrison and Siegel (1991) in which learning disabled children are defined as those who </p><p>(1) have IQ scores equal to or above 80 and (2) have one or more of the following: (a) WRAT (Wide Range Achievement Test) read- ing subtest scores equal to or below the 25th percentile, (b) WRAT arithmetic subtest score equal to or below the 25th percentile and WRAT reading scores equal to or above the mean on the Parent and or Teacher Question- naire. (Conners Parent and Teacher Rating Scales; see Goyette, Conners, &amp; Ulrich, 1978, p. 91) This definition captures three high-incidence </p><p>disorders within learning disabilities: reading (word recognition), arithmetic (computation, written work), and attention. Consistent with the notion that a learning disability is intrinsic to the </p><p>child, each of these disorders is shown to dem- onstrate neurological and cognitive processing profiles (e.g., Fletcher, 1985). No doubt, such a definition presents a number of positive (e.g., easy identification for a broad constituency of re- searchers) and negative (e.g., construct validity, conceptual integrity) aspects. Of course, the ma- jor advantage in selecting this range of behaviors is that researchers utilize a common set of mea- sures that, in turn, enhance our chances of repli- cation. </p><p>Less restrictive definitions would attempt to capture operations that match some basic pre- mises in the field, most likely the following three assumptions: (a) learning difficulties are not due to inadequate opportunity to learn, general intel- ligence, or significant physical or emotional dis- orders, but to basic disorders in psychological processes; (b) these processing deficits are a re- flection of neurological, constitutional, and/or biological factors; and (c) there is a deficit that depresses only a limited aspect of contextually appropriate behavior. </p><p>Thus, when one attempts operationally to de- fine a phenomenon such as learning disabilities, an effort is made to measure adequate opportu- nity to learn (documentation that optimal sys- tematic instruction has occurred, but deficits in isolated processes remain); independence of spe- cific processing difficulties from general aca- demic aptitude (independence of a processing problem from general IQ); the relationship be- tween neuropsychological inefficiencies and cog- nitive processing difficulties; and so on. Criteria for selection of learning disabled children might include cut-off points on intellectual, neuropsy- chological, dynamic, and information-processing measures. However, problems arise when one attempts to expand the number of operations into a definition. Some of these problems relate to the limited number of valid and reliable instru- ments available (e.g., Kavale &amp; Mundschenk, 1991) and the weak link between neurological and cognitive indices (Orbzut &amp; Boliek, 1991). Function of Indicators </p><p>The value of...</p></li></ul>

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