effects of science teachers' epistemological beliefs in teaching

JOURNAL OF RESEARCH IN SCIENCE TEACHING VOL. 33, NO. 1, PP. 47-63 (1996)

Effects of Science Teachers’ Epistemological Beliefs in Teaching

Maher Z. Hashweh

Department of Education and Psychology, Birzeit University, Birzeit, West Bank, via Israel

Abstract

In recent years there has been a renewed interest in investigating teachers’ beliefs in general, and science teachers’ epistemological beliefs in particular. However, very few studies have investigated the effects of these epistemological beliefs in teaching. The purpose of this study was to test the hypotheses that teachers holding constructivist beliefs (a) are more likely to detect student alternative conceptions; (b) have a richer repertoire of teaching strategies; (c) use potentially more effective teaching strategies for inducing student conceptual change; (d) report more frequent use of effective teaching strategies; and (e) highly valuate these teaching strategies compared with teachers holding empiricist beliefs. Through the use of a three-part questionnaire consisting of critical incidents, direct questions about teacher strategies of conceptual change, and ratings of the use and importance of specific teaching strategies, data were obtained from 35 science teachers with different science backgrounds and teaching at different educational levels. Analy- sis of the data supported all five hypotheses. The findings are discussed in terms of their implications for further research.

The last few years have witnessed a realization that research on teacher thinking will not provide us with adequate understanding of teacher behaviors, and that the study of teacher beliefs might provide a more promising approach to better understand teacher behaviors (e.g., Clark, 1988; Fenstermacher, 1979, 1986; Nespor, 1987). In a review of research on teachers’ believes, Pajares (1992) argued that although “teachers’ beliefs can and should become an important focus of educational inquiry . . . this will require clear conceptualizations, . . . and proper assessment and investigation of specific belief constructs” (p. 307). Science teachers’ epistemological beliefs is a specific belief construct that has been the focus of many recent studies in science education (e.g., Benson, 1989; Billeh & Malik, 1977; Carey & Stauss, 1968; Gallagher, 1991; Hashweh, 1991; Hodson, 1985; King, 1991; Nadeau & Desautels, 1984; Prawat, 1992).

Very few studies, however, have examined the effects of these beliefs in teaching, although such studies could provide important construct validation for the assessment of epistemological beliefs. Etchberger and Shaw (1992), for example, traced the change in a science teacher’s beliefs about teaching and learning and how these beliefs influenced her teaching methods. Martens (1992), while also studying a science teacher in change, documented how the teacher’s beliefs inhibited the implementation of a problem-solving approach to teaching elementary science. Benson (1989), Gallagher and his students (Gallagher, 1991) and Hashweh (1985) are

0 1996 by the National Association for Research in Science Teaching Published by John Wiley & Sons, Inc. CCC 0022-4308/96/010047-17

48 HASHWEH

among a small number of researchers who investigated the effects of teachers’ epistemological beliefs in science teaching. Benson (1989) showed that, whereas situational factors/constraints influence the classroom curriculum, teachers’ beliefs exert a great influence on that curriculum. The teachers’ teaching practices that relied on the lecture method and the mere presentation of information were traced to the realist conception of knowledge that these teachers held. Gal- lagher and his students (Gallagher, 1991) found that the majority of science teachers held traditional positivistic views of science that emphasized the “scientific method” and the objective nature of science. These teachers did not devote any time to teaching aspects of the nature of science except when it was included in the introductory sections of the textbooks they used. In these cases, they presented a traditional positivistic view of science, even when the textbooks portrayed a more constructivist view of science. Hashweh (1985) showed that constructivist teachers had a richer repertoire of teaching strategies than nonconstructivist teachers and that these constructivist teachers tended to use teaching strategies that were potentially more effective in inducing conceptual change.

The studies described used interpretive or qualitative research methodologies with small samples. Although there is still a need for similar studies that carefully describe how specific and well-conceptualized beliefs affect specific teaching behaviors, there also is a need for large- scale studies that employ hypothesis-testing quantitative methodologies. The present study could be considered a step in such a direction. This study is aimed at comparing specific teaching practices of two groups of teachers holding different epistemological beliefs in order to test specific hypotheses about the effects of epistemological beliefs in teaching.

Specifically, the study attempted to test the following hypotheses:

1 . Constructivist teachers detect more student alternative conceptions than do empiricist

2. Constructivist teachers have a richer repertoire of teaching strategies than do empiricist

3. Constructivist teachers use teaching strategies that are potentially more effective in

4. Constructivist teachers report more frequent use of the potentially more effective

5. Constructivist teachers place greater value on the potentially more effective strategies

teachers.

teachers.

inducing conceptual change compared with empiricist teachers.

strategies than do empiricist teachers.

than do empiricist teachers.

[These hypotheses were formulated from the results of previous studies (Hashweh, 1985). An explication of the different facets of the constructivist and empiricist beliefs is found in Hashweh (1991), whereas the criteria used in ordering the strategies according to their potential effectiveness are explained below.]

Method

Sample and Procedure

The sample of the study consisted of 35 Palestinian science teachers living in the central area of the West Bank. In a previous study (Hashweh, 1991), 91 teachers responded to a questionnaire on teachers’ beliefs about knowledge and learning. Teachers who chose a “constructivist” answer to two thirds of the items on any of the knowledge or learning subquestion- naires (who scored between 66.7 and 100) were considered to hold constructivist beliefs on that subquestionnaire. Teachers who chose “empiricist” answers to two thirds of the items on a subquestionnaire (who scored 33.3 or less) were considered to hold empiricist beliefs on that subques-

EFFECTS OF SCIENCE TEACHERS’ BELIEFS 49

tionnaire. Thus, there were two constructivists groups [Learning Constructivists (LC) and Knowledge Constructivists (KC)] and two empiricist groups [Learning Empiricists (LE) and Knowledge Empiricists (KE)] . These groups were not mutually exclusive; consequently, some teachers belonged to two groups simultaneously. The total number of teachers in these four groups was 49 (53.8% of the original sample).

Learning constructivist teachers .emphasized the active role of the learner in constructing knowledge to understand the world. They were aware that students develop many ideas on their own, and that many of these ideas are inconsistent with orthodox science. Consequently, they acknowledged that learning in science is often a conceptual change process, and that teaching science involves confronting students’ alternative conceptions. In contrast, learning empiricists emphasized the role of external reinforcement in learning, did not believe that students develop ideas in science on their own, were not aware of the existence of alternative conceptions, and advocated neglecting students’ alternative conceptions if they exist.

Knowledge constructivist teachers believed that the aim of science was to develop theories to understand the world, absolute objectivity was impossible (observations are theory-laden), testing theories against experience was more important than their origins, scientific knowledge was tentative and invented, and emphasized the importance of scientific revolutions and conceptual change. In contrast, knowledge empiricists believed that the aim of science was to collect facts about the world, scientific knowledge was objective, permanent, and discovered (rather than invented), and emphasized the role of observations, the “scientific method” and the gradual and accumulative aspects of the growth of scientific knowledge (rather than the conceptual change aspect).

A year later the 49 constructivist and empiricist teachers identified through the process described were asked to respond to another questionnaire. The researcher distributed the questionnaires to the teachers in their schools and collected them personally 1 week later. Thirty-five teachers (71%) responded. Table 1 describes the composition of the sample.

Instruments

Background. A paper-and-pencil questionnaire consisting of three parts was constructed to probe the effects of teacher beliefs about learning and knowledge in teaching. The aspects of teaching that the questionnaire examined were the numbers and types of teaching strategies used by teachers. For the purpose of this study a strategy was defined as a series of instructional actions for obtaining specific results.

The construction of the questionnaire was guided by previous theoretical and empirical

Table 1 Numbers of Teachers Who Responded to the Questionnaire

Teacher group No. responding Percent of No. receiving

Constructivists Learning 16 Knowledge 6

Learning 6 Knowledge 18

Empiricists

69.9 75.0

75.0 72.0

Note. Eleven teachers of those responding belonged to two groups simultaneously.

50 HASHWEH

studies (Hashweh, 1985, 1986; Posner, Strike, Hewson & Gertzog, 1982). On the theoretical side, if student learning in science is considered to entail, in some cases, a conceptual change process, and if some important conditions that facilitate conceptual change are identified (Hash- weh, 1986), then teaching strategies can be classified according to their potential effectiveness in inducing conceptual change. Accordingly, in this study, strategies involving explanations of science knowledge and/or repetition were classified as the least effective strategies.

A second type of strategies are those that facilitate acquisition, assimilation, and acceptance of new scientific concepts. These strategies involve the use of different knowledge representations (examples, analogies, demonstrations, student activities) or attempt to convince the student of the “truth” of the orthodox science or to “prove” it. In many instances, this type of strategy shows how orthodox science successfully explains a certain phenomena. This second type is considered as a more effective type of strategy.

A third type of strategy involves confronting student alternative conceptions, that is, attempts to “discredit” student alternative conceptions. Attempts to “refute” these alternative conceptions may involve providing counter evidence in the form of anomalous phenomenon or showing the discrepancy between the student’s alternative conception and the orthodox science that the student already accepts. Consequently, these strategies emphasize either the conflict between the student’s alternative conception and some part of the real world, or the conflict between the alternative and the orthodox science conceptions (Hashweh, 1986). This third type of strategy was classified as more effective than the second type in inducing conceptual change.

A fourth type of strategy aims at facilitating cognitive restructuring, that is, at helping the student resolve the two types of conflict. This is usually attempted through showing how alternative conceptions are not totally wrong, but limited, and through defining the “domain of explanation” of each of the alternative conceptions and the scientific ones. Sometimes, this strategy involves showing how orthodox science explains the alternative conception, that is, how the alternative conception is a special case of the scientific conception. In other words, “synthesizing schemata” are provided by the teacher to help the students in cognitive restructuring (Hashweh, 1986, p. 246). Finally, this fourth type can involve providing opportunities for the students to ask questions to reinterpret past experiences after the scientific conceptions are accepted. The fourth type of strategy was classified as more effective than the previous types in inducing conceptual change.

Finally, the most effective method of inducing conceptual change was considered to involve the use of multiple types of strategies. Teachers who help students acquire new scientific conceptions, who confront student alternative conceptions, and who help their students to reorganize their cognitive structures are using potentially more effective means than teachers who use only one type of strategy (for example, confront alternative conceptions only).

On the empirical side, it was previously found that teachers who hold constructivist beliefs about learning (and probably knowledge) had a richer repertoire of teaching strategies compared to teachers who did not hold such beliefs. In addition, these teachers tended to use strategies that were potentially more effective in inducing conceptual change (Hashweh, 1985). Therefore, it was decided to construct the items of the questionnaire to examine the teaching strategies that teachers use in details.

The Questionnaire. The first part of the questionnaire asked the teacher to respond to two “critical incidents.” Each incident described a classroom situation in which a student’s response indicated the possible presence of an alternative conception. The teacher was asked hidher opinion about the student response, and was asked the line of action to take if he/she was in that


classroom. The incidents were developed after a review was conducted of some of the common alternative conceptions in science, and in some cases some of the tasks used in previous studies of student alternative conceptions in science were modified for the purpose of the present study. Eight incidents were developed, two in each of the areas of physics, chemistry, biology, and general elementary science. Each teacher received only two incidents appropriate to hidher background in science. This was done because previous work has shown that teachers could discover student alternative conceptions only in areas in science in which the teachers them- selves were experts (Hashweh, 1985). Presented are four of the eight incidents. Each incident ended by asking, “1) What do you think of that answer?, and 2) what would you do at that moment if you were in that teacher’s place?’

Physics Critical Incident: The teacher asked students to identify the force or forces acting on a small object (a piece of chalk) if it is thrown vertically upwards after it has left the person’s hand while moving upwards. The teacher asked the students to represent each force with an arrow whose length and direction correspond to the magnitude and direction of the force. A student drew the following diagram on the blackboard. [A diagram of an object with two forces acting on it is provided. A long vertical arrow represents an upward force labeled “the force of thrust,” and a shorter arrow represents a downward force labeled “the force of gravity.”]

Chemistry Critical Incident: A teacher placed a drop of acetone in a test tube and closed it tightly with a cork. He heated the tube on a Bunsen burner until the drop of acetone evaporated, then he asked, “If we weigh the test tube before and after heating, will we detect a change in weight or will the weight stay the same?’ One of the students answered, “The weight of the tube will decrease after we heat it because the vapor is lighter than the liquid.”

Biology Critical Incident: While teaching about living things, the teacher asked, “What is the process of respiration?” One of the students answered, “It is the process of inhaling oxygen and exhaling carbon dioxide in animals, and the process of inhaling carbon dioxide and exhaling oxygen in plants.”

Elementary Science Critical Incident: The teacher asked, “What do you expect to happen if you travel on the earth’s surface in a straight line without stopping?’ “When we reach the earth’s edge we shall fall down in space,” answered a student.

The second part of the questionnaire included an introductory paragraph explaining about alternative conceptions and the research revealing that students hold these conceptions in science. The teachers were asked if they have a strategy or strategies for dealing with student alternative conceptions, and to explain the strategylstrategies if it/they exist. The third part of the questionnaire described six strategies and asked the teachers to rate them on a 3-point scale according to their previous use and importance (often, sometimes, and never; very important, important, and not important).

The six strategies are described (in a somewhat summarized form compared to the way they appeared in the questionnaire, where the strategies were described in more detail and with no labels) and ordered from the least to the most potentially effective in inducing student conceptual change.

1. Explain: Emphasizing the scientific conceptions only (and students will discard their alternative conceptions if these conceptions are neglected by the teacher).

52 HASHWEH

2. Repeat: Repeating the explanations (repetition will finally induce conceptual change). 3. Convince: Offering examples, phenomena, or thought experiments that “prove” or

confirm the scientific conceptions. 4. Refute: Offering examples, phenomena, or thought experiments that refute or contra-

dict the students’ alternative conceptions. 5. Develop: Developing student ideas until they become clear and explicit, and then

confronting these ideas. 6. Restructure: Comparing scientific and alternative conceptions and explaining the rela-

tions between the two types of conceptions in an attempt to resolve the conflict between them.

The three parts of the questionnaire moved from the use of indirect open-ended techniques to direct closed-ended techniques of assessing teacher use of strategies in dealing with student alternative conceptions.

Data Analysis

The teachers’ evaluation of the student responses described in the critical incidents were analyzed in an effort to categorize them according to type. The researcher was particularly interested in examining if the teacher considered the student’s answer as acceptable, and if he/she discussed the alternative conceptions that might be related to the student’s answer. The teachers’ responses were classified into four types (with examples of responses categorized under that type).

Qpe I: Answer Is Acceptable Answer is correct (only) Answer is acceptable (only)

Q p e 11: Answer Is Unacceptable Answer is wrong (only) Answer is incomplete (only)

Qpe 111: Alternative Conception Identifies and names the alternative conception Explains the alternative conception Discusses the alternative conception Shows previous awareness of presence of the alternative conception among students

Qpe IV: Other No response Could not be classified

In analyzing the responses to the teachers’ reactions to the critical incidents (about what they would do if they were in that teachers’ place) and answers to the direct question about the strategies used in dealing with alternative conceptions, the data were examined for numbers and types of strategies used. Although the previous theoretical work offered a schema for classifying the strategies according to type, this schema was not used in the first phase of analysis to determine if other types could be discovered (but whose “presence” the schema would conceal). Teacher responses were categorized using descriptive categories close to the responses them- selves. When it was found that teachers’ responses could not be classified in any other manner,


the previously described schema was used in the second phase of analysis, and the different descriptive categories obtained in the first phase were collapsed to fit the previously described types of strategies. The following shows the different types of strategies and the different descriptive categories collapsed under each.

Type I: Explanation and Repetition Explains the “right” answer Explains an “incomplete” answer provided by a student Repeats the explanation

Type 11: Assimilation (Convincing) Explains through the use of knowledge representations (examples, models, etc.) Explains through “proof,” usually a phenomenon or experiment Shows how science “explains” the phenomenon

Type 111: Refutation Shows discrepancy between science and alternative conception Describes anomalous phenomena

Type IV: Restructuring Shows how science explains alternative conception Provides opportunities for questions and reinterpretation of past experience

The responses to the third part of the questionnaire (rating six strategies according to importance and use) were analyzed to determine the percentages of teachers who considered the different strategies important or who reported frequent use of the strategy.

Finally, the analyzed data were examined to detect differences between the different teacher groups (two constructivists and two empiricists groups).

Results and Discussion Teacher responses to the different items of the questionnaire are presented to show differ-

ences between the constructivists and the empiricists groups. In addition, the actual responses of four teachers, representing the two groups, are presented and analyzed. Two were male teachers who graduated from a 2-year college-level teacher training institute, and both were teaching science at the same school in a Palestinian refugee camp near the city of Bethlehem. One of them, teacher C 1, held constructivist beliefs about both knowledge and learning, whereas the other, teacher E l , held empiricist beliefs about both knowledge and learning. The other two teachers, C2 and E2, representing the constructivist and the empiricist groups, respectively, were secondary school physics teachers holding Bachelor degrees in physics, and both were working in private schools in Jerusalem.

Teacher Evaluation of Student Answers in Critical Incidents and Strategies Used in Response to these Incidents

Teachers were asked to evaluate student answers that reveal the possible existence of alternative conceptions in two critical incidents. Figure 1 shows that a larger percentage of teachers in the two empiricists groups found the answers acceptable than did teachers in the two constructivists groups. The majority of the empiricist teachers found the answers wrong or

54

Figure I. teacher groups.

Percentages of types of reactions to the two critical incidents by different

incomplete whereas a much smaller percentage of the constructivists teachers labeled them so. In contrast, most of the constructivist teachers identified the alternative conceptions revealed by the student answers, whereas a much smaller percentage of the empiricist teachers were able to identify the alternative conceptions. Thus, constructivist teachers were more likely to be strict in evaluating student responses that reveal the existence of alternative conceptions and to identify the alternative conceptions present.

Teacher El’s response to the critical incident in which the student answers that if she travels on the Earth’s surface without stopping she would reach the Earth’s “edge” and fall down in space illustrates empiricists’ response to such a task:

We cannot walk in a straight line on the Earth’s surface because it is not a plane. Therefore when someone travels along a curved line on the Earth’s surface, he will return to the point of departure, and will not fall in space.

This teacher only pointed to the fact that the student’s answer is wrong. He objected to the teacher’s question because it used the term “straight line”; he was not aware that the student’s beliefs, that the Earth is flat and that there is an absolute “down” direction, led to the described answer.

The empiricist physics teacher, E2, responded to the Physics Critical Incident in a similar manner; his response shows that he failed to identify the student’s alternative conception:

The force in the upward direction is a momentary force that acts on the object only when it is in touch with the person’s hand. . . . Therefore, when it is moving upward the only force acting on it is the force of gravity in the downward direction, and this force makes the object decelerate. . . . The representation given by the student is momentary at the instant the object is thrown, while the question asks about the phase after the object has been thrown. The representation is wrong and the correct representation is this [“correct” representation is drawn].

In comparison, the constructivist teacher Cl was sensitive to the student’s ideas that led to the answer, as his response shows:

1) This student’s answer indicates that the student has a prior false concept which is that the Earth is flat and not spherical. This concept is directly related to the part of the


Earth that he directly experiences through his senses; he cannot perceive more than he sees. This concept should be corrected. I start by making the child question the truth of this concept, and ask, “With the availability of airplanes and cars, do you think man is now capable of reaching the edge of the Earth? Did you hear about anyone falling from the edge of the Earth? Have you been to the sea? How is its surface like? Why can’t we see the other side of the sea even with the use of binoculars?

2) After that I move to explaining the correct alternative (the Earth is spherical). And the answer to the question would be “he will return to the place of departure.” I bring a football and ask the students to draw lines along its circumference. “Where did you reach in the end?’ [I ask]. I also would bring a model of the Earth and pass my finger along its circumference after pointing to a point of departure using a piece of chalk. “Where did we reach?’ [I ask].

3) I answer students’ inquiries about the new concept, such as, “Why doesn’t the water in the seas spill if the Earth is spherical?”

4) I mention examples that prove that the Earth is spherical, and these should be concrete, such as, the existence of the horizon.

Physics teacher C2 was also able to identify the alternative conception. He explained that students relate the force to velocity, and not to acceleration. That is, he was aware that students hold Aristotelian rather than Newtonian notions about movement. His answer shows that he had previously identified the conception and had developed strategies that deal with it:

This is a wrong answer of course, but is very expected in the lesson about forces [empha- sis added]. In such cases, I ask the student some questions about the concepts in the lesson. If I discover that he does not understand the concepts well I explain the concept and the definition of the force and its relation with acceleration and not velocity. . . . This requires a long and detailed presentation that involves. . . .

After that, I ask the student to rethink about his answer. If he does not reach the required answer I ask, “Which is bigger in your diagram, the force of thrust or the weight?’ Therefore, in which direction is the object accelerating? Here, the student will discover that according to his diagram the object will accelerate in the upward direction because the net force is upward, which means that the object will never fall down. . . . I finally shall ask further questions and give further examples to make sure that the student understood the concept of the lesson.

The four teacher’s responses were analyzed to exemplify the differences between the two groups of teachers with regard to the identification of and awareness about student alternative conceptions. However, it is important to analyze the responses with regard to the types of strategies used in response to the incidents. The empiricist teachers’ responses indicate that these teachers had one strategy to deal with student alternative conceptions: they explain the “correct” answer.

In comparison, the constructivist teachers, C1 and C2, showed that they used a combination of strategies in such cases. Teacher C1 used a “confrontation” or refutation strategy by using counterexamples or “anomalies” (no evidence of anybody falling off the Earth’s “edge,” the limit to seeing the other side of the sea, the horizon) to make the student question her alternative conception. The teacher also used representations in the form of models (the football and the model of the Earth) to help the student accept the scientific conception, a strategy that we labeled “convince.” However, this teacher (and other constructivist teachers as well) used the anomalies to question the student’s alternative conception and to demonstrate the “correctness” of the scientific conception at the same time. Finally, the teacher used a third strategy, one that facilitates cognitive restructuring, by giving the student the chance to ask questions (expecting

56 HASHWEH

that the student might accept the idea that the Earth is spherical but still needs to wonder why the water in the seas does not spill down because she has not changed the other conception she holds about an absolute “down” direction with a relative “down” direction directed to the center of the Earth).

Examination of teacher C2’s response to the Physics Critical Incident shows that he used two of the three strategies used by teacher C1. He used an assimilation (convincing) strategy by explaining how the scientific conception can successfully explain the phenomena. He used a confrontational strategy as well by showing the student that her answer was unreasonable because it entails that objects thrown vertically upwards would accelerate rather than decelerate. He did not use the strategy of facilitating cognitive restructuring that teacher C1 used.

The numbers of strategies used by all teachers in response to the critical incidents are shown in Figure 2. It is clear that constructivist teachers used more strategies when confronted by incidents revealing alternative conceptions. Moreover, these teachers tended to use multiple types of strategies, an approach that has been previously described as the potentially most effective approach in inducing student conceptual change.

Analysis of the types of strategies used by the different teacher groups shown in Figure 3 reveals that the least effective strategy of explanation was used infrequently by constructivist teachers, whereas the great majority of empiricist teachers resorted to using this strategy when faced with student answers revealing alternative conceptions. The more effective strategies of convincing (assimilation), refutation, and cognitive restructuring were used by a larger percentage of constructivist teachers compared to empiricist teachers. It is worth pointing out that empiricist teachers rarely used the highly effective strategies of refutation and restructuring, whereas many constructivist teachers used these two strategies. In summary, constructivist teachers tended to use potentially more effective strategies and empiricist teachers tended to use less effective strategies in inducing conceptual change.

Teacher Responses to Direct Questions About Their Strategies

In the second part of the questionnaire teachers were asked if they use a specific strategy or strategies for dealing with student alternative conceptions, and were asked to explain the strategy or strategies that they use if they answered affirmatively. Although there were no large differences between the proportions who claimed they had such a strategy or strategies in the

NO. of Single Strategies

0 No. of Multiple Strategies

LC KC LE KE Teacher Group

Figure 2. two critical incidents by different teacher groups.

Number of strategies per teacher per critical incident used in response to the


Explain

M

W

20

0 LC KC LE IE

Taachar Omup

Refute

Convince hen.

60

W

30

10

0 LC KC L€ KE

Taachor Omup

Restructure

Taachar Dmup Taachar Omup

Figure 3. incidents by different teacher groups.

Percentages of different types of strategies used in response to the two critical

two groups, analysis of the teachers’ explanations of the strategies they use showed that constructivist teachers reported a larger number of single-type and multiple-type strategies compared to empiricist teachers (see Figure 4). This corroborates the results found in the first part of the questionnaire as presented in Figure 2.

The responses of the four teachers can be used to illustrate these results. Both empiricist teachers mentioned only the use of assimilation strategies, which we labeled “convince”:

Teacher El

1 use feedback and connect the prior information to new information to enrich the new concept. For example, students think that if glass is subjected to a flame it breaks. In the laboratory they see that we use glass flasks that do not break when heated. I explain that we use a special kind of glass with a specific coefficient of expansion so that it does not break,

58

1.4

HASHWEH

NO. of Sinole Strategies

LC KC LE

Teacher Group

KE

Figure 4. groups as their strategies of conceptual change.

Number of strategies per teacher described by teachers in different teacher

Teacher E2

1. I emphasize the correct scientific concepts. 2. I give examples that demonstrate the truth of these concepts.

In contrast, teachers C1 and C2 used a variety of strategies as the following responses

Teacher C1 reveal.

I follow the following steps:

1. I cause the student to doubt the prior concept by asking questions about different aspects of the concept and how they are wrong.

2. 1 propose alternatives to these different aspects. 3. 1 gather the different aspects to form a complete scientific concept. 4. 1 ask questions and allow students to ask questions to anchor the new concept. 5 . I use scientific activities and other means if possible. 6. 1 compare the results of using the old concept with the results of using the correct

concept.

Teacher C2

Changing students’ concepts cannot be done by writing a group of laws on the blackboard but through the use of experiments that help the student deduce the required concept. Sometimes we use experiments that prove that the way the student thinks about a certain concept is wrong. Most importantly, the student should reach a stage of self conviction without causing him shame or embarrassment.


Examination of these responses reveals not only differences in the numbers of strategies used, but in the types as well. Teachers El and E2 used assimilative strategies only. Teachers C1 and C2 used confrontation strategies as well as assimilative strategies.

The strategies described by all teachers as their strategies for dealing with alternative conceptions were classified into three types (Figure 5). None of the teachers reported the use of Type I strategy (explanation and repetition), although the responses to the first part of the questionnaire revealed that about 25% of the constructivists and more than 50% of the empiricists resort to that strategy (Figure 3).

In agreement with the result from the first part of the questionnaire, it can be seen from Figures 5 and 3 that constructivist teachers actually used and reported the use of the strategies of refutation and restructuring to a much greater extent than did empiricist teachers. As for the strategy of assimilation (convincing), Figure 5 shows that more empiricists than constructivists reported its use, in contradiction with the results of actual use presented in Figure 3. The reason for the discrepancy is that whereas teachers in both groups did not report the use of the explanation strategy, in actuality a larger percentage of empiricists used the explanation strategy. In summary, constructivist teachers tended to report the use of a larger number of single-type and multiple-type strategies of conceptual change, and tended to report greater use of the more effective strategies of refutation and restructuring compared with empiricist teachers.

Teacher Rating of Importance and Use of Diflerent Strategies

Teachers were requested in the third part of the questionnaire to rate six teaching strategies according to importance and previous use. Figure 6 shows the trend lines for the percentages of teachers in each group that rated any particular strategy as very important (three on a 3-point scale). It is clear that constructivists tended to rate the more effective strategies as more important compared to the empiricists.

70

60

E 50

: D

a 40

30

20

10

0

LC KC

I LE

Teacher Group

Convince

0 Refute

Restructure

t KE

I

Figure 5. groups as their strategies of conceptual change.

Percentages of different types of strategies described by teachers in different

60 HASHWEH

Learning Subscore Knowledge Subscore PUG.",

loor

2ot - 4aL 20

O L : 01 : SXIIu. l l -AT COIvI*cL UIWE W E L O P M S T I Y C N I E O(CLII. UKAI COWVINC, MIW, D M O , WT""C1"M

Strategy Strategy - con.UUc~.U + Enp.(d.r. - Com-dwht. + Enp6sl.l.

Figure 6. strategy as very important.

Trend lines for percentages of teachers in different teacher groups rating the

Figure 7 shows the trend lines for the percentages of teachers in each group that reported frequent use of any particular strategy (three on a 3-point scale). Again, it is clearly evident that constructivist teachers tended to report more frequent use of the more effective strategies compared to empiricist teachers.

In summary, constructivist teachers considered the more potentially effective strategies as more important and reported more frequent use of these strategies compared with empiricist teachers. The results of the third part of the questionnaire corroborate the results obtained from the previous two parts of the questionnaire.

Summary and Conclusion

When faced with critical incidents in which a student's response indicated the possible presence of an alternative conception, empiricist teachers were more likely than constructivist teachers to accept these answers. Additionally, although the majority of empiricist teachers found the answers wrong or unacceptable, the majority of the constructivist teachers identified the probable alternative conceptions held by the students that lead to such answers.

In responding to these student answers, the constructivist teachers used a greater number of

Learning Subscore Knowledge Subscore PERCENT

1w - PERCEWT 100-

ao . 00 - +

.o- 6 0 -

20 - m - . 0 : 0 :

+

I-," -I cmm Dlypw m m m Dw* llou, 0- -"TI Dnuw -CNm STRATEGY STRATEGY

-cornM*v(* +h$+hn --* +FJlwd.a

Figure 7. frequent use of the strategy.

Trend lines for percentages of teachers in different teacher groups reporting


single- and multiple-type teaching strategies, revealing richer repertoires of teaching strategies. Additionally, constructivist teachers used the potentially more effective teaching strategies more frequently than the empiricists, who used the less effective strategies more frequently.

When directly asked about their strategies of conceptual change, constructivist teachers reported a greater number of single-type and multiple-type strategies, and more frequent use of the more effective strategies of conceptual change when compared with the empiricists.

Finally, when asked to rate different strategies according to their frequency of use and importance, constructivist teachers reported more frequent use and higher valuation of the more effective strategies.

The similar results obtained from the three different sections of the questionnaire in which different means to investigate the teaching strategies used by the teachers were employed provide strong converging evidence and validation for the findings. It is worth pointing out that the fact that the responses of constructivists or empiricists to the first part of the questionnaire, in which teachers received different critical incidents in accordance with their fields of specializa- tion (physics, chemistry, biology, or general science) were similar, irrespective of the critical incident used, also lends strong converging evidence in support of the hypotheses being studied.

A previous study (Hashweh, 1985) that used intensive interviews with six secondary school teachers in the United States and that focused on the teachers’ beliefs about learning (and only incidentally about their beliefs about knowledge) led to the formulation of the hypotheses of the present study. The present study, using a different methodology (questionnaires to access teacher beliefs about both learning and knowledge and to investigate the teaching strategies used by these teachers), population (school and college teachers), and conducted in a different culture (Palestinian teachers in the West Bank), revealed results that support these hypotheses (i.e., yielded similar results). Consequently, the effects of science teachers’ epistemological beliefs in teaching seem to be strong and stable across teachers’ field of expertise in science, the educational level at which they teach, or the culture to which they belong. Finally, the fact that a period of 1 year separated the assessment of the teachers’ beliefs and the investigation of the teaching practices of those teachers in the present study lends support to the claim that teachers’ epistemological beliefs are stable traits that strongly influence teaching.

The results of the present study reveal the effects of teachers’ epistemological beliefs in teaching in general. The results are in agreement with those of other studies that investigated the influence of epistemological beliefs in teaching (Benson, 1989; Gallagher, 1991). In addition, the present study revealed the positive effects of constructivist teachers’ beliefs in using more effective strategies for inducing student conceptual change in particular. In view of these results, it becomes important to ask how these beliefs develop, and how resistant or amenable they are to change. Studies that address these questions are needed.

Finally, the results of this study, which revealed that constructivist teachers are better prepared than empiricist teachers to induce student conceptual change, are not surprising. Constructivist teachers view the development of knowledge at the individual level and in science as a process of conceptual change. Hence, they are more sensitized to student alternative conceptions and are able to infer their presence from student responses in the classroom. Additionally, these teachers have viewed science learning and teaching as a process of conceptual change, and, consequently, have developed strategies to induce that change. It is not surprising that the successful strategies they have developed on their own are the potentially more effective ones on theoretical grounds. These effective strategies (such as the use of multiple-type strategies that help acquisition of new conceptions, confront alternative conceptions, and facilitate cognitive restructuring) are more in harmony with the teachers’ constructivist beliefs than other less effective strategies, such as the presentation of information and

62 HASHWEH

repetition-strategies that are incongruent with constructivist beliefs. An interesting question that arises from these findings is if the influence of these epistemological beliefs is limited in its effects to teacher behaviors, or if it exceeds teacher behaviors to affect student conceptual change. Studies that investigate the relationships between teacher beliefs and student learning outcomes, in general, are worth conducting.

References

Benson, G.D. (1989). Epistemology and science curriculum. Journal of Curriculum Stud- ies, 21, 329-344.

Billeh, V., & Malik, M.H. (1977). Development and application of a test on understanding the nature of science. Science Education, 61, 559-57 1.

Carey, L., & Stauss, N.G. (1968). An analysis of the understanding of the nature of science by prospective secondary science teachers. Science Education, 52, 358-363.

Clark, C.M. (1988). Asking the right questions about teacher preparation: Contributions of research on teacher thinking. Educational Researcher, 17(2), 5- 12.

Etchberger. M.L. & Shaw, K.L. (1992). Teacher change as a progression of transitional image: A chronology of a developing constructivist teacher. School Science and Mathematics, 92, 411-417.

Fenstermacher, G.D. (1979). A philosophical consideration of recent research on teacher effectiveness. In L.S. Shulman (Ed.), Review of research in education (Vol. 6, pp. 157-185). Itasca, IL: Peacock.

Fenstermacher, G.D. (1986). Philosophy of research on teaching: Three aspects. In M.C. Wittrock (Ed.), Handbook of research on teaching (3rd ed., pp. 37-49). New York: Macmillan.

Gallagher, J. J. (1991). Prospective and practicing secondary school science teachers’ knowledge and beliefs about the philosophy of science. Science Education, 75, 121-133.

Hashweh, M.Z. (1985). An exploratory study of teacher knowledge and teaching: The effects of science teachers’ knowledge of subject-matter and their conceptions of learning on their teaching. Unpublished doctoral dissertation, Stanford University, California.

Hashweh, M.Z. (1986). Toward an explanation of conceptual change. European Journal of Science Education, 8 , 229-249.

Hashweh, M.Z. (199 1). Palestinian science teachers’ epistemological beliefs: A search for the constructivist teacher. Paper presented at the Sixth International IOSTE Symposium on World Trends in Science and Technology Education, Palm Springs, CA.

Hodson, D. (1985). Philosophy of science, science and science education. Studies in Science Education, 12, 25-57.

King, B.B. (1991). Beginning teachers’ knowledge of and attitudes toward history and philosophy of science. Science Education, 75, 135-141.

Martens, L.M. (1992). Inhibitors to implementing a problem solving approach to teaching elementary science: Case study of a teacher in change. School Science and Mathematics, 93,

Nadeau, R., & Desautels, J. (1984). Epistemology and the teaching of science. Ottawa:

Nespor, J. (1987). The role of beliefs in the practice of teaching. Journal of Curriculum

Pajares, M.F. (1992). Teachers’ beliefs and educational research: Cleaning up a messy

150- 156.

Science Council of Canada.

Studies, 19, 311-328.

construct. Review of Educational Research, 62, 307-332.

EFFECTS OF SCIENCE TEACHERS' BELIEFS 63

Posner, G.J., Strike, K.A., Hewson, P.W., and Gertzog, W.A. (1982). Accommodation of a scientific conception: Toward a theory of conceptual change. Science Education, 66, 211- 221,

Prawat, R.S. (1992). Teachers' beliefs about teaching and learning: A constructivist per- spective. American Journal of Education, 100, 354-395.

Received April 4, 1994 Revised April 21, 1995 Accepted June 6, 1995

effects of science teachers' epistemological beliefs in teaching

Documents