Development of an Instrument for Measuring Secondary School Students' Understanding of Pressure

The aim of this study is to develop an achievement test consisting of multiple choice questions about the topic of pressure covered in the secondary school science curriculum. In order to ensure the validity of the achievement test, it was decided, as a result of examination by 2 science experts and 2 science teachers, to remove 5 items which were not found suitable in terms of student level and scope. The piloting of the 20-question achievement test constructed as a result of expert opinion was carried out. For the purpose of reliability and validity checks, the achievement test was given to 200 grade 7 students who were studying in state schools in four of the metropolitan cities in Turkey in the spring semester of the 2018-2019 academic year. In order to determine the reliability of the achievement test, the internal consistency coefficient of KR-20 was calculated and the KR-20 internal consistency coefficient was found as .73. The analyses of the data showed that the 20-item achievement test is reliable and valid