Development of Simple Multiple-Choice Diagnostic Test of Acid-Base Concepts to Identify Students' Alternative Conceptions

Alternative conception is students' conception of scientific concepts that are inconsistent with the conception of scientists. Various studies show that alternative conceptions of chemical concepts occur in students, including acid-base concepts. Various identification of alternative conception methods have also been developed, including a simple multiple-choice diagnostic test. Although not too accurate, simple multiple-choice diagnostic test is easy to develop, use, and analyze, but useful enough to identify students' alternative conceptions. The aims of the study are to develop a valid and reliable simple multiple-choice diagnostic test instrument of acid-base concepts and to identify alternative conceptions of 11th grade students and first year university students of Chemistry Program. This descriptive research design was conducted in two stages 1) development of valid and reliable of simple multiple-choice diagnostic test of acid-base concepts and (2) identification of students' alternative conceptions. Analysis of instrument validity and reliability was performed based on response of 184 students of 11th grade students and 133 first year university students of Chemistry Program who had studied acid-base concepts before. While the identification of students' alternative conceptions was conducted to 59 students of 11th grade and 40 first year university students of Chemistry Program. Analysis to response of 11th grade students indicate that 8 of the 25 test items of the acid-base concepts developed in this research were invalid. Five invalid items that have a negative or very low Pearson correlation coefficient were removed, the rest having better Pearson correlation coefficient refined and used to identify students' alternative conception. The final version of the instrument has a Cronbach's alpha reliability of 0.537 (medium grade) for 11th grade students and 0.470 (upper low grade) for first year university students. The results of the data analysis show that the alternative conceptions of acid-base concepts occurring in the 11th grade students are more extent and intense than that occurs in the first year university students of Chemistry Program. These can be caused by the difference of age, concept ecology, learning motivation, learning fidelity, and discipline background between 11th grade students and first year university students of Chemistry Program.