In-Depth Analysis of Misconceptions as a Basis for Developing Research-Based Remedial Instruction: The Case of Photosynthesis.

PHOTOSYNTHESIS iS one of the most important biological topics. It is repeatedly taught in school at different age levels. In the last decade a number of studies on student misconceptions focused on photosynthesis (Arnold & Simpson 1980; Wandersee 1983; Smith & Anderson 1984; Bell 1985; Haslam & Treagust 1987; Stavy, Eisen & Yaakobi 1987; Eisen & Stavy 1988; Barker & Carr 1989a). These studies contain detailed as well as comprehensive information about students' ideas regarding plant nutrition and photosynthesis. It appears that the time has come to move ahead and concentrate on the development of strategies that will help students overcome the barriers to understanding which have been uncovered by the research mentioned above. Descriptions of misconceptions are very important starting points. Such descriptions are the products of diagnostic studies usually based on interviewing a small number of students, sometimes followed by a paper and pencil test with larger samples. Analysis of students' responses to such instruments yields the percentage of students selecting a particular distractor (on a multiple choice item) or giving an answer (in response to an open question), which can be identified as representing a particular misconception. Based on such data, conclusions as to the frequency of different types of misconceptions can be drawn. This process has already lead to the development of remedial material for use in middle or junior high school classrooms (Arnold & Simpson 1980; Roth & Anderson 1985; Eisen & Stavy 1989; Barker & Carr 1989b), and for university students who did not major in biology (Bishop, Roth & Anderson 1985). The limited success of the module developed by Bishop et al. (1985) as reported by Anderson (1984) stresses the need to base such efforts on a better understanding of students' difficulties. Our efforts to achieve a better understanding of prevalent misconceptions focused on 11th and 12th grade high school students who specialized in biology. These students know many facts and hold a rich repertoire of ideas about photosynthesis which they had constructed in previous years. Still, some of their ideas may not be in line with accepted scientific notions. Obtaining in-depth insight into the ideas about photosynthesis was an important step which we believe had to be taken before embarking on the development of remedial materials for the high school population. Although students' misconceptions related to photosynthesis have been reported by several researchers, this study adds two important dimensions. First, it employs more than one instrument to study a particular concept, thereby identifying sources for particular misconceptions. Second, innovative instructional strategies that were effective in creating conceptual change in students are described.