| Summary: | 碩士 === 國立彰化師範大學 === 科學教育研究所 === 97 === The study aimed to investigate the conceptual changes of the 8th grade students learning “solving quadratic equation with one unknown by completing the square.” The major research method was the case study of the qualitative research methodology along with quantitative analysis. The participants were 36 8th grade students in Taichung County. In the first stage, the participants’ conceptual changes in “solving quadratic equation with one unknown by completing the square” were diagnosed. The 5E instructional activities and worksheets were designed to be administered in remedial instruction. After that, the participants’ conceptual changes were analyzed. In the second stage, six participants were chosen and their conceptual changes were investigated through interviews. Data collection included a pretest, posttest, worksheets, students’ reflections, video data of classroom observation, and interviews.
The results of this study were as follows.
1.The types of students’ alternative concept were: (1) confusing polynomial with equation (2) ignoring the coefficient of in quadratic polynomial with one unknown can be negative (3) ignoring the negative square root (4) Using across-multiplication and unable to solve the quadratic equation with one unknown (5) concepts of multiplicative identities are wrong and unable to complete the square.
2.The main causes of alternative concept were: (1) the disturbance of other concepts (2) the interpretation of instructors (3) the instrumental understanding.
3.After applying the 5E instructional model in “solving quadratic equation with one unknown by completing the square”, there were salient effects on 8th grade students’ conceptual changes.
4.The adoption of 5E instructional model was more helpful for middle and low-level students.
5.The conceptual changes mainly occurred in the stages of “exploration” and “explanation.”
Key Words：Completing the square, Quadratic equation with one unknown, 5E instructional model, Alternative conception, Conceptual change.
|
|---|
