Data collection

The data collection consisted of two parts, that is, a semi-structured interview to investigate the teachers’ general pedagogical knowledge and pedagogical content knowledge (PCK) of models and modelling, and a questionnaire to investigate their subject matter knowledge of models and modelling in science. The interview and the questionnaire were conducted to the teachers by the first author of this article.

2.4.2.1 Semi-structured interview

With all teachers, a semi-structured interview was held. The interview questions were developed on the basis of the results of a study of the relevant literature on teacher knowledge, on the one hand, and models and modelling in science education, on the other hand. The initial interview schedule was tested on four PUSc. teachers (not among the nine participants in the study). As a result of this pilot study, some interview questions were rephrased or replaced in the interview schedule. Two new questions were added to the scheme. The final interview consisted of four parts. Parts 1 and 2 included questions that were indicators for the teachers’ general pedagogical knowledge: for example, What do you think is the best way for students to learn? Do you think that teaching has an impact on students’ learning? If so, what can you do to improve students’ learning? To get more insight into the teachers’ pedagogical perspectives, we also asked them to comment on a selection of metaphors, representing the three perspectives on knowing, learning, and teaching (Greeno et al., 1996). These metaphors (Table 2.3) were taken from studies by Ebbens (1994), Fox (1983), and Martinez (2001).

The metaphors were presented to the teachers on small cards. The teachers were asked to read the metaphors aloud, and to make comments. This gave the teachers the opportunity to react freely to all aspects of each metaphor (Oolbekkink-Marchand, 2003). The use of metaphors was a way to activate the teachers’ personal knowledge and beliefs about learning and teaching, and help them express this knowledge.

Table 2.3 Some metaphors about learning and teaching used in the interviews

Perspective Metaphors about learning (part 1) Interpretation from the

perspective of learning

Behaviourist Learning is storing data Learning has taken place if the quantity of knowledge has increased

Constructivist Learning is acting like a detective who looks for things and into things

Learning is the consequence of dealing actively with the environment in the construction of knowledge Situative Learning is joint work, as done by ants

collaborating to achieve a result which is beneficial to all

Learning is a consequence of authentic participation in the activities of a community of practitioners

Perspective Metaphors about teaching (part 2) Interpretation from the

perspective of teaching

Behaviourist A teacher is a gardener who gives every plant in his garden what it needs

It is the teacher’s task to motivate students and organize learning activities, feedback, and reinforcement Constructivist It is the teacher’s task to arrange a

construction site for students and deliver the necessary materials

The teacher should create exploratory and interactive learning environments Situative Teaching is acting like a tourist guide who

negotiates a destination and a route with the tourists.

The curriculum should reflect a set of commitments about the kinds of activities that students should learn to participate in

Parts 3 and 4 of the interview included questions which aimed at eliciting the teachers’ PCK of the learning and teaching of models and modelling in PUSc. To make this subject more concrete (to the teachers), a series of questions was asked on Chapter 3 of the ANtWoord workbook titled: ‘Solar system and Universe’ (Domain F). In the context of this chapter, the teachers were questioned about the four knowledge elements of PCK mentioned earlier (see section 2.2), namely, knowledge about (1) instructional strategies concerning a specific topic, (2) students’ understanding of this topic, (3) ways to assess students’ understanding of this topic, and (4) goals and objectives for teaching this topic in the curriculum. In the context of this chapter, the topic focused on was ‘Models of the Solar System’.

All interviews took place privately in a place chosen by the teacher (e.g., the teacher’s classroom, or a small office), shortly after he had finished the chapter on the solar system and universe. A cassette recorder was used to tape the conversation. Probing and clarification techniques (Emans, 1989) were applied when the teachers’ answers were considered as not relevant, not clear, or incomplete. The interviews took one hour to one and a half hours. Afterwards, all interviews were transcribed in full. This

involved a direct transcription of all utterances, with added symbols to capture long pauses, hesitation, stressed words, and laughter.

2.4.2.2 Questionnaire

To chart the teachers’ understanding and subject matter knowledge of models and modelling in science, a questionnaire was used, which had been developed by the second and third authors of this article, as part of a study on new teachers in PUSc. (Van Driel & Verloop, 1999).

This instrument encompasses four sections, of which we used only one in our study. This section focuses on the teachers’ understanding of and beliefs about scientific models and the act of modelling, and consists of two scales (Table 2.4): (1) statements on the relationship between a model and its target (11 items), and (2) statements on the construction and use of models in a social context (8 items). These statements were scored on a four-point scale, ranging from 1 = never, through 2 = sometimes and 3 = mostly, to 4 = always.

Table 2.4 Scales within the questionnaire on models, and sample items

Scales Sample scale - items

Relating models and targets A model is a simplified reproduction of reality A model is meant to explain a phenomenon One attempts to keep a model as simple as possible Social context of models Creativity is a major factor in the development of

models

A model depicts the ideas of scientists

The development of a model is guided by questions of the researcher

In the study by Van Driel and Verloop (1999), 2.99 was the mean score on the first scale (standard deviation 0.40; Cronbach’s alpha 0.75), and 2.76 was the mean score on the second scale (standard deviation 0.38; Cronbach’s alpha 0.64).

The nineteen items were presented to the teachers in written form, and items from the two scales were alternated. At schools with more than one participant, the teachers answered the questions in the same room, at the same time. Completion of the questionnaire took about half an hour.

2.5 Analysis