Haluk Özmen

The influence of computer-assisted instruction on students' conceptual understanding of chemical bonding and attitude toward chemistry: A case for Turkey

In this study, the effect of computer-assisted instruction on conceptual understanding of chemical bonding and attitude toward chemistry was investigated. The study employed a quasi-experimental design involving 11 grade students; 25 in an experimental and 25 in a control group. The Chemical Bonding Achievement Test (CBAT) consisting of 15 two-tier questions and the Chemistry Attitude Scale (CAS) consisting of 25 item were the principal data collection tools used. The CBAT and CAS instruments were administered in the form of a pre-test and post-test. Analyses of scores of the two groups in the post-test were compared and a statistically significant difference was found between groups in favor of experimental group. It also seems students from the experimental group were more successful than the control group students in remediation of alternative conceptions. The results of this study suggest that teaching-learning of topics in chemistry related to chemical bonding can be improved by the use of computer-assisted teaching materials.

Determination of students' alternative conceptions about chemical equilibrium: a review of research and the case of Turkey

This study aims to determine prospective science student teachers’ alternative conceptions of the chemical equilibrium concept. A 13-item pencil and paper, two-tier multiple choice diagnostic instrument, the Test to Identify Students’ Alternative Conceptions (TISAC), was developed and administered to 90 second-semester science student teachers enrolled in CHEM 102 Chemistry II course in spring 2006, after they received fourteen 50-minute regular course instruction concerning the equilibrium. The content validity of the test was established by the panel consisting of lecturers. The Spearman-Brown reliability for the test was 0.71. Analysis of the results collected with the TISAC show that students did not acquire a satisfactory understanding of the chemical equilibrium concept. For the first tier of the test items, the range of correct answer was 48.8% to 78.8%. When both tiers were combined, the correct response was reduced to a range of 22.2% to 48.8%. In this study, seventeen alternative conceptions were also identified through analysis of the TISAC. These conceptions were grouped under the headings of the application of Le Chatelier’s principle, reliability of the equilibrium constant, heterogeneous equilibrium, and the effect of a catalyst.

The Effectiveness of Conceptual Change Texts in Remediating High School Students' Alternative Conceptions Concerning Chemical Equilibrium

This study investigated the effectiveness of conceptual change texts in remediating high school students’ alternative conceptions concerning chemical equilibrium. A quasi-experimental design was used in this study. The subjects for this study consisted of a total 78 tenth-grade students, 38 of them in the experimental group and 40 of them in the control group. A questionnaire, the Alternative Conceptions about Chemical Equilibrium Test (ACCET), was developed and administered to students as a pretest and posttest. While the experimental group received a conceptual change text instruction, the control group received a traditional style instruction. The results of the study indicated that the students in the experimental group showed significantly greater levels of achievement than the students in the control group. Moreover, in both groups the percentages of students’ alternative conceptions decreased in the however the experimental group did better than the control group.