Development of a two-stage diagnostic test on earth science topics: Validity and reliability study

Misconceptions, often stemming from personal experiences and false beliefs, arise when an individual's understanding of a subject differs from that of an expert in the field. Given the prevalence of misconceptions, especially in a subject with rich content and abstract concepts like science, it is necessary to conduct studies to determine the prevalence of these misconceptions among students and to identify them specific to the unit, as failing to correct these misconceptions can adversely affect the entire educational experience. In this context, the present research aims to develop a two-stage diagnostic test to identify the misconceptions of 6th-grade students regarding the Sun, Earth, Moon, and Planets. As part of the research, a two-stage diagnostic test consisting of 21 items was developed. The item pool, prepared by considering commonly identified misconceptions in the literature, was evaluated by 12 different experts, and the Lawshe content validity index was determined to be 0.95. Reliability and validity analyses of the measurement tool were conducted with a study group of 349 students from five different middle schools in the Siverek district of Şanlıurfa province. Analyses using Microsoft Excel and JASP programs calculated the Cronbach's Alpha coefficient of the measurement tool as 0.811. Based on the results of item analysis, item difficulty, item discrimination, and confirmatory factor analysis tests, it was decided to remove four items from the measurement tool. The two-stage diagnostic test, consisting of 17 items, was determined to be a reliable and valid measurement tool that can be used to identify misconceptions regarding the Sun, Earth, Moon, and Planets.