Research on science teacher knowledge - Lit Review by Abell (2007)

Abell, S. K. (2007). Research on science teacher knowledge (Chapter 36). In S.K. Abell and N.G. Lederman (Eds.), Research on Science Teacher Education, pp.1105-1149, New York: Routledge.

This chapter is a comprehensive literature review of the research on science teacher knowledge.

Science teacher subject matter knowledge (SMK)

Using a true/false written test, researchers found that prospective elementary teachers (Ralya & Ralya) and practicing teachers (Blanchett) held a large number of misconceptions about science and science-related issues. The Ralya and Ralya study is interesting in that misconceptions they identified for a significant number of teachers became key targets for research on both student and teacher science conceptions 50 years later (e.g., causes of the seasons, force and motion, heat and temperature).

"Teachers often subscribe to the same alternative conceptions as their students" (p. 189), (Wandersee, 1994)
Few studies have examined the development of science teacher SMK over time. Arzi and White (2004) investigated SMK in a 17-year longitudinal study of secondary science teachers. They found that the school science curriculum was "the most powerful determinant of teachers' knowledge, serving as both knowledge organizer and knowledge source" (p. 2). This study is significant both for the rarity of its longitudinal methods as well as the resulting phase model of teacher SMK development that could be a useful tool in science teacher education.

Appleton (1992, 1995) claimed that factors other than increased science study affected confidence to teach science but admitted that teachers who experienced success in learning science content did become more confident. Appleton also warned science educators not to confuse confidence with competence.
A review of the research on teacher SMK about chemistry (de Jong et al., 2002) corroborates the observation that even teachers who have strong preparation in chemistry lack understanding of concepts fundamental to their field. ... students across disciplines, including preservice teachers, gave incorrect answers about the causes and consequences associated with this phenomenon. Indeed, problems in understanding college chemistry are not limited to prospective elementary teachers.

Another line of science teacher research concerned itself with teacher planning. Although this research typically did not mention Shulman or PCK, being more often framed by a teacher cognition perspective, notions of teacher knowledge were often implicit. The planning literature in teacher education is rich (see Clark & Peterson, 1986; So, 1997), but science education is not well represented. Science education studies on teacher planning have examined both preservice (Davies & Rogers, 2000; Morine-Dershimer, 1989; Roberts & Chastko, 1990) and practicing (Aikenhead, 1984; Sanchez & Valcarcel, 1999; So, 1997) science teachers in an attempt to understand how teachers plan and what knowledge and beliefs influence their planning.

Two other studies of SMK in earth and space science (Barba & Rubba, 1992; 1993) were substantially different in that they adopted an expert/novice theoretical framework to study inservice/preservice and novice/veteran teachers' declarative and procedural knowledge about a variety of earth and space science topics. Aligned with their theoretical frame, they found that expert teachers had better content knowledge structures, gave more accurate answers, used information chunks in solving problems, solved problems in fewer steps, and generated more solutions. Novice teachers moved between declarative and procedural knowledge more often and were less fluent in solving earth/ space science tasks overall.

SMK Assessment Methods: card sort, concept mapping, true-false tests, organize topics, comment on topic importance. Rather than provide the terms used in the card sort, the researchers (Gess-Newsome and Lederman, 1993; 1995) asked teachers to first generate their own terms and then diagram the relationships.
By far the most research on teachers' SMK in science has taken place in the domain of physics. The overall finding from these studies of teacher SMK in physics is that teachers' misunderstandings mirror what we know about students. This finding holds regardless of the method used to assess teacher knowledge: true / false (Yip et al., 1998), multiple choice (e.g., Lawrenz, 1986), open-ended surveys (Mohaptra & Bhattacharyya, 1989), interviews (Linder & Erickson, 1989; Smith, 1987), and observation techniques (Daehler & Shinohara, 2001; Pardhan & Bano, 2001).

Relation of SMK to Teaching

Druva and Anderson (1983) found a small but significant positive relation between "science training" and "teaching effectiveness."

In an observational study of elementary science teachers, Anderson (1979) provided convincing evidence that, "Lack of science content [knowledge]... made it virtually impossible for them to structure the information in lessons in ways preferred by science educators" (p. 226); the teachers avoided spontaneous questions from students, emphasized minor details in discussion, and failed to develop important concepts.

Dobey (1980) demonstrated the complexities of correlating SMK with teaching. Dobey, in his dissertation (Dobey, 1980; Dobey & Schafer, 1984), studied 22 preservice elementary teachers' SMK and level of inquiry teaching via their planning and teaching of a pendulum unit to fifth graders. The researchers measured SMK, not by the number of college science courses taken, but by performance and training on topic-specific tasks. The findings were mixed. Teachers in the "no knowledge" group were more teacher-directed than those with "intermediate knowledge," but not more so than the "knowledge" group teachers. The "no knowledge" teachers did not pursue new avenues of investigation during the lesson and allowed the least number of student ideas. The "no knowledge" group did not give out pendulum information in the lesson, and one-half of the "knowledge" group lectured at some point. [too little or too much SMK was associated with teacher-directed instruction; perhaps the teachers with high-SMK taught science they way they learned science]

In her dissertation study of five experienced biology teachers, Gess-Newsome (Gess-Newsome & Lederman, 1995) compared the teachers' subject matter structures with their classroom practice, concluding that the "level of content knowledge had a significant impact on how content was taught" (p. 317). [Qs the teachers ask, amount of "risky activities," complexity of test questions, amount of teacher vs. student talk]
Smith (1997): "knowledge of science does enhance teaching, but not in a straightforward manner" (p. 151).

Examining preservice elementary teachers as they planned a science lesson, Symington and Hayes (1989) demonstrated that inadequate SMK led to limitations in planning, and that future teachers had few strategies for coping with their lack of science understanding. However, in another study, Symington (1982) found no direct relationship of SMK to a preservice teacher's ability to plan appropriate materials for student investigation. According to Symington, there must be other kinds of knowledge and abilities that "compensate for a lack of scientific knowledge" (p. 70).

Despite this mixture of settings and methods, the evidence does support a positive relationship between SMK and teaching.

Could it be, as Lederman and Gess-Newsome suggested, that some minimal SMK is necessary, but that studies at different grades, or with preservice versus practicing teachers, cannot be compared fairly? Or could it be that SMK does have an effect on science teaching, but that this effect is mediated by other types of teacher knowledge? This was implied in many of the studies reported. Perhaps SMK is necessary, but not sufficient, for effective teaching. A review of studies of PK and PCK could be instructive.

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SCIENCE TEACHER PEDAGOGICAL KNOWLEDGE

Shulman's Model of Teacher Knowledge: pedagogical content knowledge (PCK) as the knowledge that is developed by teachers to help others learn. Teachers build PCK as they teach specific topics in their subject area. PCK is influenced by the transformation of three other knowledge bases: subject matter knowledge (SMK), pedagogical knowledge (PK), and knowledge of context (KofC) (Grossman)

The Shulman program was substantially different. Shulman and his colleagues attempted to answer the question "What knowledge is essential for teaching?" by studying teachers from different subject areas (e.g., English, science, social studies).

Magnusson, Krajcik, and Borko (1999) defined PCK as consisting of five components: (a) orientations toward science teaching, which include a teacher's knowledge of goals for and general approaches to science teaching; (b) knowledge of science curriculum, including national, state, and district standards and specific science curricula; (c) knowledge of assessment for science, including what to assess and how to assess students; (d) knowledge of science instructional strategies, including representations, activities, and methods; and (e) knowledge of student science understanding, which includes common conceptions and areas of difficulty.

Grossman's (1990) formalization of Shulman's model of teacher knowledge included a component of pedagogical knowledge separate from PCK that she labeled general pedagogical knowledge (PK). PK includes knowledge of instructional principles, classroom management, learners and learning, and educational aims that are not subject-matter-specific. Theoretically, these types of knowledge interact with PCK for teaching of a particular topic in a discipline. Could it be that the influence of PK on PCK needs to be better articulated? I believe that more attention must be paid to the interaction of PK with PCK-for example, the role of caring, classroom management, or general learning views-in how teachers teach science.

SCIENCE TEACHER PEDAGOGICAL CONTENT KNOWLEDGE

Pedagogical content knowledge (PCK) has been defined as "the transformation of subject-matter knowledge into forms accessible to the students being taught" (Geddis, 1993, p. 675). Grossman (1990) and later Magnusson et al. (1999) defined separate components of PCK, including orientations, knowledge of learners, curriculum, instructional strategies, and assessment. Yet, the PCK literature in science education is not nearly as tidy as the SMK literature.

Several lines of research used frameworks other than Shulman's to understand science teacher knowledge. For example, science education researchers have used Schon's theory of reflective practice to understand the development of "professional knowledge" (Abell, Bryan, & Anderson, 1998; Anderson, Smith, & Peasley, 2000; Munby, Cunningham, & Lock, 2000; Munby & Russell, 1992; Russell & MWlby, 1991). These studies demonstrated how teacher knowledge develops over time with respect to various inputs and perturbations, but did not classify teacher knowledge as Shulman did.

Subcategories of PCK

1. orientations: "general way of viewing or conceptualizing science teaching" - (e.g., fact acquisition, conceptual development, and content understanding); approaches to teaching (e.g., transmission, inquiry, discovery)
2. knowledge of learners: requirements for learning certain concepts; areas students find difficult, approaches to learning science, and common alternative conceptions; many teachers were unaware of students' likely misconceptions [teachers have many of the same misconceptions student have]; veteran teachers are able to predict and plan around these difficulties; experienced teachers are able to provide evidence to support their interpretations of students. Overall it appears that teachers lack knowledge of student conceptions, but that this knowledge improves with teaching experience.
3. curriculum knowledge: (a) knowledge of mandated goals and objectives (e.g., state and national standards); and (b) knowledge of specific curriculum programs and materials. Although science teachers recognize a variety of goals for science teaching, they tend to emphasize content goals over attitudinal or process goals. We know little about the knowledge teacher bring to bear on the analysis, selection, or design of science curriculum materials.
4. knowledge of science instructional strategies: (a) subject specific strategies (e.g., learning cycle, use of analogies or demos or labs); and (b) topic-specific teaching methods and strategies, including representations, demonstrations, and activities. More science education research should be devoted to examining what teachers understand about classroom inquiry strategies and science teaching models, and how they translate their knowledge into instruction.
5. science assessment: this includes (a) what to assess, and (b) how to assess (methods); According to Briscoe (1993), a teacher's ability to change his/her assessment practices is "influenced by what the teacher already knows or understands about teaching, learning, and the nature of schooling" (p. 983). These studies of teacher knowledge of assessment in science provide rich research models that demonstrate a link between PCK for assessment and science teaching orientation. More studies are needed to better understand what teachers know about assessment, and how they design, enact, and score assessments in their science classes.

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Implications

Science teacher education must honor not only formal teacher knowledge, but also the local and practical knowledge of teachers in the field and the sociocultural contexts that frame their work.
Current U.S. federal policy implies that only SMK is needed to produce highly qualified teachers (U.S. Department of Education, 2002). This review provides evidence to the contrary.

Recommendations for Future Research
The area in which the SMK literature is less clear is the relation of SMK to other forms of teacher knowledge, to teacher beliefs and values, and to classroom practice. We need more studies that take place within the teaching -context to examine how SMK develops, how it plays out in teaching, and how it is related to other kinds of teacher knowledge (see Ball & McDiarmid, 1996).

More studies need to focus on the essence of PCK-how teachers transform SMK of specific science topics into viable instruction (see van Oriel et al., 1998).

Although we have a good understanding of the kinds of knowledge that teachers bring to bear on science teaching, we know little about how teacher knowledge affects students.

The ultimate goal for science teacher knowledge research must be not only to understand teacher knowledge, but also to improve practice, thereby improving student learning.