مرکز منطقه ای اطلاع رساني علوم و فناوري - DevelopingTwo-Tier Diagnostic Instrument to Determine Misconceptions on Radioactivity

Abstract :

The aim of this study is to develop two-tier diagnostic instrument to determine misconceptions on radioactivity and study on validity and reliability of this test. Two-tier instruments are effective measuring tools to determine misconceptions, minimizing the negative sides of interviews and multiple choice tests. In order to develop two-tier diagnostic instrument, a method was used on three main stages, determining the content, learning about students’ misunderstandings and developing diagnostic instrument. Besides, methods suitable for literature were used to measure validity and reliability. The research sample consists of 244 science teacher candidates in a state university. Reliability of the instrument, difficulty index and distinguishing index of items were determined according to the analysis of item and instrument. Mean item difficulty index of the total test was 0.45; first stage mean item difficulty index was 0.47 and second stage mean item difficulty index was 0.49. KR-20 reliability coefficient of the first stage of the test was 0.68, while KR-20 reliability coefficient of the second stage of the test was 0.70. The content and construct-related evidence of validity were studied for validity of the instrument. Hypothesis test method was used for construct-related validity and the instrument was determined to have construct-related validity. A two-tier diagnostic instrument consisting of 18 items to determine misconceptions on the subject of radioactivity was developed as a result of this study.