Research in Science Education, 1992, 22, 30 - 37

PHYSICS TEACHERS' ACTION-RESEARCH EXPERIENCE WITH A TEACHING MODULE ON "FORCE"

Andrew Baimba University of Papua New Guinea

ABSTRACT

Eight physics teachers from three research schools working in collaboration with the author developed, tried, and evaluated a teaching module on "Force". The module was designed for students in a non- western society, for whom there is no cultural term that explicitly defines the concept. This paper describes illustrative examples of the trials and evaluation exercise of the module. It concludes with a summary of the effects the teachers' interaction with the module had on their professional development.

INTRODUCTION

A recent trend in science education has been the realization that students hold alternative conceptions of scientific phenomena. These misconceptions, as they are often caUcd, are difficult to change, and are based on the students' everyday experiences of the world. The concept of force in physics is one of those phenomena about which students have alternative conceptions that are quite different from the scientific ones (Gilbert, Osborne & Fensham, 1982; Gilbert & Watts, 1983). However, Rowell, Dawson & Lyndon (1990) observed that while there has been a wealth of published research identifying misconceptions on the understanding of scientific concepts by students, relatively little has appeared detailing how these misconceptions can be rectified. Berg and Brouwer (1991) further state that one of the challenges facing today's researchers is to develop strategies for teachers' use in trying to correct students' alternative conceptions. The work reported in this paper was an attempt in that direction.

The paper describes a teaching module on Force designed for junior secondary school students in a non-western society (Sierra Leone), for whom there is no cultural word that explicitly defines the concept of force. The aim of the module was to help these students acquire the scientific understanding of the concept. The exercise was part of a study designed to investigate an educational change process through introducing science teachers to an innovative approach to teaching of physics at the junior secondary school level (ages 12-14). The sample comprised eight science teachers selected from three schools in Bo, Sierra Leone. The study began with an examination of these teachers' prior perceptions about the junior secondary school science programme. This was undertaken by means of interviews and classroom observations of the eight teachers, lasting for three months. A two-week in-service programme followed during which the teachers were introduced to the ideas of a constructivist-based science for all curriculum by the author (see Baimba, 1991). Subsequently, an action-research programme which involved these teachers working in collaboration with the author to develop, try, and evaluate teaching modules on Measurement and Force was undertaken. This paper describes the module on force together with illustrative examples of the action- research programme through its trials and evaluation.

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SIERRA LEONIAN CONCEPTIONS OF FORCE

The laws of physics are expressed as relations between physical quantities. Force is a physical quantity and concept such as work and power are all related to it. Many examples of application of the knowledge of force exist in the Sierra Leonean traditional setting: These include lifting a load or drawing water from a well using pulleys, constructing stable structures such as houses and bridges, and balancing and carrying a load on the head.

In spite of these diverse applications, there is no Sierra Leonean word for the concept of force. The closest practical reference or suggestion of the concept is through action words such as rub, lift, compel, etc. which are regarded as complete ideas in themselves. In the Sierra Leonean mind these suggest no underlying abstract concept of force which is common to all. The aim of the module on Force was to highlight experiences that would help students studying the concept for the first time in a science lesson to:

develop an understanding of the scientific meaning of the term 'force'; identify and qualitatively describe different kinds of forces in activities; and be familiar with some of the effects of common types of force.

everyday

MODULE

To achieve these aims, a teaching module was designed and patterned along the constructivist approach of teaching and learning science (Driver & Oldham, 1986). The module advises a teaching strategy comprising of four stages: exploration of students' ideas, development of the concept, application of the learned concept, and evaluation (see Figure 1.)

ACTION-RESEARCH TRIALS AND EVALUATION OF THE MODULE

The module was taught in four sessions: two double periods of 80 minutes duration and two single periods of 40 minutes duration in any one particular stream. One teacher from each of the three research schools, was assigned two streams of Form 2 students. This was to facilitate the trials and retrials of teaching units of the module by the same teacher on different streams of students. Using the module, weekly lesson plans were developed by individual teachers. The action-research consisted of a cyclic process of trial - evaluation - modification and retrial of the respective lesson plans.

The trial exercise was monitored by the author and the heads of the science departments from the three research schools through classroom observations and interviewing. The interviews were of two types. There were after-lesson interviews during which the author and the particular teacher jointly evaluated the lesson, often leading to modifications in subsequent lesson plans for retrial. Also, regular weekend meetings were held during which the author and teachers co-planned work for the following week. The following section illustrates proceedings of some of the trial lessons.

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Les~on 1

The aim of the first lesson was to establish the importance of studying a unit on 'force', and solicit students' prior conceptions on the topic. To introduce the lesson, one of the experimental teachers engaged students in the following dialogue:

Teacher:

Pupili Teacher: Pupils: Teacher: Pupils(Chorus) Teacher: Pupils(Chorus) Teacher: Pupil: Teacher: Pupils:

Who can tell me why people are not allowed to drive vehicles with smooth tyres? Because the police will arrest them. Why will the police arrest them? (No response) Has any of you tried to walk on a polished floor? Yes Is it difficult or easy? It is difficult Why is it difficult? It is slippery? Why is it difficult to walk on a slippery surface? (No response)

At that point, the teacher wrote the word Force on the board and continued the conversation as follows:

Teacher: Pupils(Chorus) Teacher: Pupils(Chorus) Teacher: Pupil 1: Pupil 2: Teacher: Pupils: Teacher: Pupil 1: Pupil 2: Pupil 3: PupiI 4:

Who can pronounce the word on the board? Force Have you come across that word before? Yes What does it mean? Force is when you force somebody to do something. Force is the energy we apply to something that makes it move. Any other meanings? (No response) Can you give me examples of Force? Police force Military force U.S. Navy Force of gravity

The teacher summed up the lesson by informing the students that they would continue the discussion in the next lesson to find out the scientific meaning and examples of force.

Lessons 2 and 3

Lessons 2 and 3 were practical classes aimed at familiarising students with examples of scientific frameworks for force. To enable them to conceptualize the scientific meaning of the term, students were engagcd in activities that illustrated examples of common types of forces - gravitational, reaction, tension, magnetic and frictional. An example of the type of activities the students were engaged in is reproduced below.

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Materials: Nails, sizeable stones, strings, clamps, wooden blocks, pulleys and scale pans.

Instructions: Use the materials provided to do the following exercises:

Tie a piece of_string around the stone. Hold it in the air by holding onto the end of the string. Does the stone fall? If no, explain what stops it from falling. If yes, explain why it fails.

Use a piece of string to tie the wooden block to the pulley. With the wooden block resting on the table, pass the connecting string over a pulley clamped at the edge of the table so that the scale pan hangs freely in air. Add the stones provided one at a time into the scale pan. Does the scale pan or the wooden block move? Explain what is stopping the scale pan and its contents from falling? What will happen to the scale pan and its content if you cut the string midway between the scale pan and the wooden block? Explain.

At the end of l~sson 3, the teachers utilized the results of the practical exercises to present students with scientific frameworks of force and examples of the common types of forces.

All experimental teachers expressed satisfaction with the students' participation in the practical activities in Lesson 2. However, two problems emerged that were common across the three research schools. Firstly, students from the three schools displayed lack of understanding of the concept of weight for bodies in equilibrium. For example, students in all three schools knew that a stone let free in the air fell because of the "pull of gravity on the stone". But when that same stone was suspended in the air by tying a string around it, the students' understanding of 'pull of gravity' became obscured. In that new frame, they could not tell what had happened to the pull of gravity because the stone no longer fell.

The following conversation between a particular experimental teacher and his class clearly depicts that problem:

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What causes the stone to fall? The force pulls the stone towards the earth. The force pulls the stone. How do we call this type of force which causes objects to fall towards the earth? Gravitational force. What generally makes things fall? Their weight Why does the stone not fall when I suspend it in the air by means of the string? It is being stopped by something. Who can tell me what that something is? (No response) Is the weight of the object still acting on it? (No response)

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The other problem was that the students tended to associate force with motion. In the exercise involving the wooden block and the scale pan, students consistently denied action of any force(s) on the scale pan as long as the wooden block remained stationary. Similarly, when asked if a student pushing a wall was applying force, the answers in all classes consisted of "Yes" and "No". Those who answered "No", on each occasion, argued that there was no force because the walls were not moving. Because of these problems, the original lesson plan of each trial teacher was modified by allocating more time to explaining the concept of weight to the students. Also, a game of tug-of-war was included as one of the class activities to help students internalize the possible frameworks that two forces acting in opposite directions could generate.

Despite the additional time spent revising the concept, students' difficulties in relating weight to other forces acting on bodies in equilibrium (e.g., a book resting on a table or an electric bulb suspended by a flex in the ceiling) persisted. On the other hand, all experimental teachers in the three research schools told the author that the tug-of-war exercise helped students to gain better understanding of the ideas that two forces acting in opposite directions might (or might not) produce motion depending on their magnitudes, and that the absence of motion did not necessarily mean the absence of force(s) in action. There might be opposition such as one team of the tug-of-war resisting being pulled by the other team.

Le~,5on 4

In Lesson 4 students were taught simple explanations for some everyday phenomena involving an understanding of the concept of force. Even though students from the three research schools were familiar with the examples selected b y their respective teachers, it was only in one school that scientific explanations for some of the examples were offered by the students. Nevertheless, students from the three schools showed great enthusiasm in this lesson, possibly because they could relate what they were learning to real life situations.

EFFECTS OF THE EXPERIENCE ON THE PARTICIPATING TEACHERS.

The major impact of the exercise on the experimental teachers concerned change in their outlook about the image of the junior secondary school science programme. During one of the after-trial interviews with the author, one of the teachers stated: "I never had clear ideas about the aims and objectives of general science curriculum. I only learnt that through participation in this study". Another teacher informed the author: "We found out that students have ideas about science even though some of these ideas are vague". The problem according to this teacher was that: "Students cannot explain these ideas and science teachers had in the past not related students' experiences to their lessons".

Another outcome of the study was the teachers' ability to develop teaching units using local resources. One teacher reported that in the past he had used textbook examples which were unfamiliar to both himself and his students to describe scientific processes in general science classes. Yet he acknowledged not using any textbook to draw up his lesson plans from the module. Apart from the advantage of making the case study teachers less dependent on textbooks, grounding the module in real life examples also minimized these teachers' total dependence on stereotyped laboratory sessions for

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science pracficals. They reported that they did not need laboratories per se to teach the module, and that the environment provided them with sufficient material to engage students in practical activities. They stressed this particukir aspect of the module as an important feature since many of their colleagues believed that science practicals could only be thought of as laboratory sessions.

Another positive outcome of the teachers' interaction with the module was the teachers' image of themselves as co-researchers. It became evident that the experimental teachers regarded themselves as researchers rather than just recipients or 'triers' of the author's ideas. Phrases like ,our work, the curriculum we have developed, our new curriculum", were identified as common descriptor~ the .experimental teachers used to refer to the new teaching packages. This is an important .outcome, because even though teacher participation in curriculum development is widely advocated, the ideas are rarely implemented in many developing countries. It also became apparent that the experimental teachers' understanding of the aims and objectives of the general science curriculum in general, as well as the nature and ways of acquiring scientific knowledge, were enhanced following interaction with the module. In particular, the Conceptual change approach that was employed in the trials of the module appealed to them as a better method of teaching science. The approach enabled them to come to terms with the idea that students had their own understanding about the concept of force even though the ideas could be classified as lay and/or gtat science (Claxton, 1984). According to these teachers, recognition of students' prior ideas enabled them to rectify students' misconceptions.

SUMMARY

This paper has presented illustrative examples of the action-research trials of the module. The results support available literature that students' conceptions of force are at times contrary to scientific ones. The citing by Sierra Leonean students of 'police', and 'military' as examples of force in physics illustrated the point. The effect on the professional development of the cxperimental teachers' interaction with the module supports finding by Bormstetter and Kyle (1986) that a well articulated in-service education programme enables teachers to portray a much more positive and exciting image of science. Nonetheless, the trial exercise was marked by difficulties that are common to curriculum innovation programmes (e.g., teachers' readiness to give practical expression to their theoretical understanding of the change process). Techniques employed to overcome this problem suggest that the establishment of conceptual clarity for the meaning of the innovation appeared to be the essential factor in arousing the experimental teachers' commitment. In this study, preliminary interview results brought vivid realisations upon the experimental teachers about how divorced school science was from the everyday experience of their students. This led to their willingness to participate in innovative curriculum research aimed at making knowledge of school science more functional for their students.

REFERENCES

Baimba, A.A. (1991). Innovation in science curriculum: A Sierra Leone case study. D.Phil thesis, University of Waikato.

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Berg, T. & Brouwer, W. (1991). Teachers' awareness of students alternate conceptions about rotational motion and gravity. Journal of Research in Science Teaching. 28 (l), 3-18:

Bonnstctter, R.J. & Kyle, W.C. (1986). A longitudinal assessment of students' and teachers' attitudes towards science in process versus traditional science classes. ERIC Document Reproduction Services No ED 270330.

Claxton, G.L. (1984). Live and learn. London: University of London Press. Driver, R. & Oldham, V (1986). A constructivist approach to curriculum development

in science. Studies in Science Education, 1__33, 105-122. Giibcrt, J.K., Osborne, R.J. & Fcnsham, P.J. (1982). Children's science and its

consequences for teaching. Scicnce Education, 6__4 (4), 623-633. Gilbert, J.K. & Watts, D.M. (1983). Concepts, misconceptions and alternative

conceptions: Changing perspectives in science education. Studies in Science Education, 1(__)), 61-98.

Rowcll, J.A, Dawson, C.J & Lyndon, H. (1990). Changing misconceptions: A challenge to science educators. International Journal of Science Education, 1._22 (2), 167-175.

AUTHOR

DR. ANDREW BAIMBA, Lecturer, Physics Department, University of Papua New Guinea. Specializations: Physics education, science education, education in developing countries.