CHAPTER 2 LITERATURE REVIEW AND MOTIVATION FOR THE STUDY
2.4 MOTIVATION FOR A REVIEW OF CONCEPTUAL DIFFICULTIES
Some students may have difficulty applying rules of logical reasoning. Herron (1996) points out the commonality of proportional relationships in concepts that cause difficulties, for example, density, stoichiometry, acceleration and rate of reaction. Following chains of formal hypothetico-deductive (logical inference such as if... then ...) or probabilistic reasoning have also been put forward as essential reasoning skills for success in science, but which are often lacking (Herron, 1975; Cantu & Herron, 1978; Lawson & Thompson, 1988). The fraction of students identified as having developed such abilities is small: 21% of a biology class with an average age of 13 years (Lawson & Thompson, 1988), 40% of a high school introductory chemistry course (Goodstein & Howe 1978) and 20% of biology students at a community college (Lawson et al., 1993). Instead of formal reasoning, students tend to use their own intuitive reasoning rules in mathematics and science (Stavy & Tiroch, 2000). Talanquer (2006) presents a model for interpreting published chemistry misconceptions in terms of students’
erroneous ideas which appear to them as ‘common sense’ and which they use in an attempt to reduce cognitive overload. It is important to identify such troublesome concepts in order to provide appropriate support for such students.
journals showed there had been a recent drop in the proportion of papers on learning (including conceptions) with a subsequent move towards research in teaching.
Recently there has been revived interest in conceptions research due to a movement towards concept-based learning (Morse & Jutras, 2008). This has prompted development of concept inventories, such as those in mechanics (Hestenes et al., 1992), basic chemistry (Mulford &
Robinson, 2002: Potgieter et al. 2005), and other disciplines such as biology and biochemistry (Howitt et al., 2008). These inventories of conceptual questions, which rely on established student ‘misconceptions’ for distractors in multiple-choice items, are well adapted to evaluating pre-knowledge and for teaching large classes, enabling a teacher to respond quickly to students’
pre-existing conceptions (Mazur, 1997).
Common student difficulties may also be avoided altogether (e.g. Johnstone, 2002) if educators are aware of them and have well-planned teaching strategies (Schmidt, 1997) (see Section 2.3.4 on chemistry difficulties being largely due to inappropriate instruction). This might involve explicit instruction, especially with non-intuitive concepts (de Vos & Verdonk, 1996), where Muthukrishna et al. (1993) claim explicit instruction can be effective in removing 90% of common alternative conceptions. It follows that resurgent interest in conceptions research is prompted by a desire to effect changes as have been called for. Accordingly, accurate descriptions of difficulties are needed. The aim of research questions 2, 3 and 4 is to provide suitable descriptions.
2.4.2 Research should drive changes in teaching
The curriculum and textbooks in chemistry have seen few changes arising from research into student conceptions. An earlier section (2.3.3) on the nature of chemistry highlighted continual but unheeded appeals from science education researchers for a more conceptually appropriate student-centred curriculum. For example, Johnstone (2000) reports that there is more concern about a logical order in which to teach chemistry rather than the psychological principles of learning. More particularly, Schmidt (1995) contends that textbook authors ignored certain misconceptions, yet teachers needed to become aware of these misconceptions if they were to address them. In the same way, Gabel (1999) observed that changes in chemistry textbooks since the 1950s had “not been driven to any great extent by research findings”. Moreover, Costa et al. (2000) found that teachers most commonly refer to textbooks for information on
practical work. So, evidently, a main source of reference for teachers’ pedagogical content knowledge (PCK) has not been highlighting research on student conceptions.
2.4.3 Pedagogical Content Knowledge
Pedagogical content knowledge (PCK), as advanced by Shulman (1986), is the form of knowledge that teachers use to transform their specialist content knowledge into suitable learning experiences. It is an amalgam of both subject specific knowledge (the conceptual structure of a subject, the validity of knowledge claims in the subject, and the value of such knowledge) and pedagogical knowledge. Shulman’s model of PCK includes the following aspects of making a discipline comprehensible for students:
• The most useful ways to represent ideas;
• The most powerful analogies, illustrations, examples, explanations and demonstrations;
• Knowledge of what makes a topic easy or difficult; that is, knowledge of common preconceptions, alternative conceptions or misconceptions;
• Strategies for organising and understanding ideas.
Further aspects of PCK are evident in recent discussions (Abel, 2008):
• PCK integrates discrete categories of knowledge and applies them synergistically to problems of practice;
• PCK is dynamic; it develops from teacher preparation, experience, and professional development.
Shulman (1987) considers PCK to be an ill-documented source of practice, unlike practice in other professions. Consequently PCK is not easily transmitted to other practitioners (Frappaolo, 2006), although Rollnick et al. (2008, p 1366) argue that if it “can be captured and portrayed, it may then be passed on to inexperienced teachers”. This has been demonstrated by van Driel et al. (2002) where a workshop, based on reported research concerning student difficulties with macroscopic and sub-microscopic levels of representation, proved to be effective in making teachers aware of such difficulties and of ways in which they could help students overcome them.
Classroom experience is currently the primary source of PCK (van Driel et al., 2002; Lee &
Luft, 2008) but Bucat (2004) is concerned that accumulated PCK does not contribute “to the collective wisdom of the profession” because it disappears when experienced teachers retire.
Like Rollnick et al. (2008) above, he recommends that educationalists systematically document the rich pool of experiential PCK, which he believes should then be evaluated formally. This suggestion may not be as simple as it sounds, for two possible reasons. Firstly, rather than being generic, Bucat argues that, in chemistry, PCK is highly specific within a discipline, which implies many interviews to cover even one topic. A second problem became evident in research by Rollnick et al. (2008). Through observations they found, as expected, that an experienced teacher displayed highly developed PCK, but they also found that he could not articulate it in an interview. It was tacit, something that he simply did. Therefore recording experienced teachers’ PCK could be a laborious process, entailing many observations, interviews or group discussions. Two aspects of PCK are especially relevant in this project. Research into student conceptions from Research questions 2, 3 and 4 could very usefully contribute to teachers’
PCK. Another aspect that needs to be captured is subject knowledge of experts which will be included in the propositional knowledge referred to in Research sub-questions 2c, 3c and 4c. As already discussed, what appears to be intuitive knowledge causing difficulties in chemistry could be tacit knowledge among subject experts (see Section 2.3.3).
2.4.4 Teachers should become aware of research
From discussion in Section 2.4.2, teachers’ lack of awareness of student conceptual difficulties is no surprise, although it is unfortunate. Furthermore, finding that student misconceptions are shared worldwide can validate much that teachers do, besides fostering their professional development (Osborne, 1996) through increased PCK. Even in 1993, Sanders had highlighted a need for research to be communicated with a target audience of educational practitioners but in 1999 Gabel claimed that nine out of ten instructors were neither aware of common misconceptions, nor of how to counteract them in class. Even much later, Drechsler and van Driel (in press) found that teachers had little knowledge of many student difficulties in acid- base chemistry that had already been published. Moreover, Costa et al.’s (2000) study showed that experienced teachers’ lack of awareness of science education research findings meant they derived their teaching knowledge instead from experience and ‘common sense’. These teachers also did not question this personal knowledge despite research having sometimes challenged its validity. Another concern is that being unaware of potential conceptual difficulties, teachers tended to overestimate their students’ performance, as shown by 64% average prediction against 41% performance on conceptual questions (Agung & Schwartz, 2007). Teachers also underestimated how deeply student conceptions were rooted (Salloum & BouJaoude, 2008). It thus appears that teachers are largely unaware of the extent and pervasiveness of student
conceptual difficulties. In addition, as discussed earlier, teachers may not be aware that they themselves hold misconceptions, which they may then transmit to students. To be specific, teachers held the erroneous belief that a single atom of sulphur would be a brittle crystalline solid, with the same melting point and density as a sample of sulphur (Kruse & Roehrig, 2005);
they also showed little conception of the space occupied by one mole of carbon atoms (Kruse &
Roehrig, 2005) or the mass of one atom of hydrogen (Ben-Zvi et al., 1988). Furthermore, teachers sometimes confuse terminology from the macroscopic domain and use it in the sub- microscopic context (de Jong & van Driel, 2001; Kruse & Roehrig, 2005). Nevertheless, reports show that discussion on published misconceptions was a useful and unthreatening way of alerting teachers to their own difficulties (Kruse & Roerig, 2005; Calyk, et al. 2005;
Drechsler, 2007). Teachers would probably welcome this inclusion: “I know chemistry, but knowing and teaching are two different things” (Kruse & Roehrig, 2005, p 1248). It appears that teachers are not resistant to and would in fact welcome this knowledge about student difficulties.
Publishing for teachers is not the same as publishing for a research community; teachers find much science education research unwieldy. Costa et al. (2000) appeal to researchers to elaborate findings so as to make them relevant for teaching practice. This is echoed in Gilbert et al.’s (2002a) plea for such potentially relevant findings to be made accessible in professional journals for chemistry teachers. All too often research remains published only in journals (Jenkins; 2000) or remains unpublished in theses and dissertations (Anderson, pers. com.) where it is then forgotten. Teachers’ workload is such that they have little time to read and work out applications for research findings; instead they need ready-made solutions to specific classroom difficulties which they encounter (Anderson, 2007). As de Jong (2004) observes: “The key problem here is that teachers expect research to be presented to them in a form they can readily apply because they are too busy doing their job to read the research literature.” However, researchers’ careers often depend on publications in peer-reviewed journals, which may cause a divide between research and practice (de Jong, 2005). Nevertheless, there has been some progress in making research findings available for educators. In this regard, an analysis of main science education journals by Viglietta (1996) showed that many were trying to address the problem of bridging research and practice, for example, adopting a more magazine-like format to some sections or inviting authors to write educator-centred articles such as the series:
“Bridging the education research – teaching practice gap” (Anderson & Schönborn, 2007; 2008;
Schönborn & Anderson, 2008a; 2008b). Attempts have also been made to publicize this
research in a suitable form through websites, for example, Anderson and McKenzie (2002), see CARD at http://www.card.unp.ac.za. These efforts to publicize the considerable body of research on student difficulties appear to be a start in effecting changes in teaching strategies.
2.4.5 The nature of research already conducted
Numerous criticisms of the nature of research on student conceptions have been made. Some research has been of low quality or poorly reported (Eybe & Schmidt, 2001). It has also been described as lacking replication studies (Sanders, 1993; Wandersee et al., 1994; Krnel et al., 1998; Jenkins, 2000; Grayson et al.; 2001; Kind, 2004). Both aspects have resulted in dismally slow progress in developing accurate descriptions of specific student difficulties (Grayson et al., 2001). As already noted, Clerk and Rutherford (2000) believe that different types of difficulties require different strategies to counter or avoid them. We need to know what we are addressing before we address it. It follows that coherent, focused and effective research giving greater insight into the nature of student conceptions is needed in order to plan effective remedial or preventative action.
Some gaps in the research field of misconceptions have been identified within specific topics (Garnett et al., 1995; Erickson, 2000), which researchers need to fill so as to provide necessary insight into student conceptions. Furthermore student conceptions in some topics have been over-researched (Grayson et al., 2001) and for these Gabel’s (1993) call to move forward should be heeded. In this regard, Tsai and Wen’s (2005) content analysis of science education research journals gives few instances of recent review papers in any field of science education.
Some general reviews of student difficulties have been published in journals (Driver & Easley, 1978; Garnett et al., 1995), in handbooks (Gabel & Bunce, 1994; Wandersee et al, 1994), or electronically (Kind, 2004). Latterly reviews have become more focused. Examples covering student conceptions in chemistry include: conceptions of matter (Andersson, 1990; Krnel et al.
1998), solutions and dissolving (Çalyk, et al., 2005a), stoichiometry (Furió et al., 2002), and chemical bonding (Özmen, 2004; Ünal et al., 2006). Research question 1 of the current project will include a review of the scope of existing research.
Systematic reviews of uncoordinated research could well provide a bridge between research and practice. These systematic reviews, as advocated by Gilbert et al. (2002a), differ from traditional review articles. Criticisms of traditional narrative reviews include authors’
complete, and possibly subjective, discretion over inclusion or exclusion of material, sometimes
with no explicit assessment of research quality (Bennett et al., 2005a). Moreover, traditional reviews may be biased towards larger studies published in top journals, while neglecting smaller but important studies (Torgerson, 2003). The ‘streamlined’ systematic review process which Bennett et al. (2005a) advocate is suitable for a narrowly focused research question to be answered through secondary analysis of published research reports. It has rigorous and replicable strategies for searching, screening and mapping these reported studies. Adapted from medical research, it has proved effective in science education (Bennett, Campbell, Hogarth &
Lubben, 2005b; Lubben et al., 2005; Bennett et al., 2007) but it seems, at the time of writing, that it has not been used for research into student conceptions.
2.4.6 Propositional knowledge in conceptions research
When Erikson (2000, p 287) advocated further research on domains where knowledge of student conceptual difficulties was lacking, he emphasised a need to include “explicit orientating frameworks”. Similarly, in their 1995 review article, Garnett et al. advocated having a list of “conceptual and propositional knowledge” (p 83) as a starting point for further research into misconceptions. Describing student conceptual difficulties as Limited or Inappropriate Propositional Hierarchy (LIPH), as suggested by Novak and Gowan (1984), shows that these propositional statements are essential; how else does a researcher adjudicate what is missing or inappropriate? I anticipated needing such a set of propositional knowledge when formulating Research sub-questions 2c, 3c and 4c. Treagust (1988; 1995) outlines a method for deriving a coherent set of propositional statements from expert knowledge. A further aspect of Treagust’s method includes developing concept maps to establish coherency or internal validity of propositions within a topic. Both aspects are important pedagogic knowledge for teachers in a discipline.
2.5 A SUITABLE TOPIC FOR REVIEW