Development and validation of the photoelectric effect concept inventory

This study aims to develop a multiple-choice instrument for determining students' concepts about the photoelectric effect. To develop the instrument, 30 students taking the Modern Physics course were interviewed to determine their misconceptions about the photoelectric effect. These misconceptions were compared with the misconceptions set out in the literature so that a decision could be made to define the questions and distractors to be used in the instrument. The content validity of the inventory was achieved on the basis of the feedback received from ten experts. The inventory was administered to 295 students enrolled in the Physics Teaching and Science Teaching Departments and discrimination index, difficulty index, and point biserial coefficient values were determined for each item. Cronbach's alpha coefficient was calculated for the whole of the test. The results of the analysis reveal that the inventory is both valid and reliable.