Students' learning in science lessons: Responses to discrepant events

Discrepant events or counter-intuitive events are science demonstrations or activities which have some unexpected or unanticipated outcomes. They have been recommended by several authors to initiate science lessons. Suchman (1966), Liem (1987) and Friedl (1986) each suggested a different teaching strategy using discrepant events to motivate students to further inquiry. This study examined students' responses to the three discrepant event teaching strategies, focusing on the level of cognitive conflict generated in students, the students' cognitive and emotional responses, and strategies they used to cope with the demands of the lesson. Comparisons were also made between the teaching strategies. A theoretical basis for the study was drawn from constructivist views of cognitive change(for example, Piaget, Kelly, Claxton, Bruner, Osborne and Wittrock and Carey), and from the problem solving literature related to science education (for example, Polya, Hayes,Green). A learning model was derived from the theoretical bases, and used to interpret the students' responses to the discrepant event lessons.The methodology involved a case study design using stimulated recall interviews with students. Video tapes of the discrepant event lessons were used to help the students recall their thoughts and feelings during the lesson, and to provide triangulated data with that from the interviews. A pilot study was conducted with twelve Year six students, and the study with six Year seven students. Case histories for the students were then assembled.Each student participated in three different discrepant event lessons taught by their regular teacher in their usual science class-room. Each student was taught using the same teaching strategy for all three lessons resulting in data being gathered from two students for each strategy.Analysis was conducted by using discourse analysis techniques to code the students' responses in the interviews and lessons. The interviews were treated as narratives rather than transparent data. A four-level hierarchical coding system was developed using a combination of inductive techniques and typological analyses. The codes were initially developed from the pilot data. The students' learning progress through the lesson was mapped onto the learning model, using one of the levels of codes. The case history data was organised into tables of descriptions of students' responses based on the codes for each lesson and presented as a diagrammatic pathway through the learning model. It was found that discrepant events were an effective means of generating cognitive conflict in science lessons, regardless of the teaching strategy in which they were used, though more complex events proved more effective. Subsequent learning, however, depended upon the information available to the students and the extent to which they accessed the information meaningfully. Learning was therefore influenced by the teaching strategy and, in particular, the social context of the lesson. A major influence on information availability and processing was the teachers' and students' expectation of closure, with the correct answer being revealed at the end of the lesson.Teaching strategies in which the teacher explained the discrepant event provided a necessary input of information not otherwise available to students. However, a teacher explanation did not necessarily result in greater understanding. Teacher-student scaffolding would seem to be more effective in very small groups. Student-student scaffolding was a key aspect of strategies including small group interaction. Students obtained information directly from sources such as the teacher's explanations, peers, and the equipment, and indirectly from the lesson context. Contextual cues included previous lesson topics, the teacher's structuring of the lesson, the teacher's actions, and the teacher's instructions (including what the teacher did not say or do).The learning model developed from constructivist theories of cognitive change was used to track students' learning progress through lessons. It was found that constructivist views alone could not adequately account for all students' responses. Social constructivist theories and students' personal motivation in the school/lesson social context also appeared to be pertinent. Revised versions of the learning model were developed to incorporate these influences. The social context of lessons also influenced how students coped with the demands of the lessons. A universal coping strategy was to seek a solution to the discrepant event, but the social conditions of the lesson constrained the students' selection of cognitive coping strategies and resulted in some non-cognitive strategies being called upon.