Students' Preconceptions of Three Vector Quantities.
This study was directed towards the identification and analysis of students' intuitive ideas or preconceptions about three kinematic vector quantities--vector position, displacement, and velocity. A list of ten implicit vector characteristics derived from a task analysis of these three vector quantities, served as the framework for the development of the interview protocols used in the study and the subsequent analysis of the data. The study proceeded in two phases; in the first, clinical-type interviews were conducted with twenty grade ten students using two tasks which involved describing the movement of a boat on a lake and a river; in the second phase, a group interview protocol (G.I.P.) requiring a written response was developed (based upon the tasks and the results of the first phase) and administered to 8 classes of grade ten students, producing a total sample of 170 subjects. Analysis of the results from the first phase yielded a small but variable number (2 to 5) number of inferred rules for each of the ten implicit vector characteristics dealt with in the individual interviews. These 'inferred rules' are hypothesized sets of beliefs (preconceptions) or cognitive structures used by the subjects to explain a problem situation posed by the interviewer. The results from the second phase of the study, in general, corroborated the findings from the first phase. While some new 'inferred rules' were identified, about 80 percent of the inferred rules used were common to those discovered in the interview sample. Hence, it would seem that the results were neither an artifact of the interview procedure, nor limited to a small group of grade ten students. The educational implications of both the rational task analysis, which yielded the list of implicit vector characteristics, and the substantive results, expressed in terms of the various sets of 'inferred rules', were discussed in terms of their applicability to classroom teachers and curriculum developers.
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- Physics: General