Exploring Students Responses on Free-Response Science Items in TIMSS

Abstract

The TIMSS (Third International Mathematics and Science Study) tests have not only an achievement aspect (How much do they know?) but also an important diagnostic aspect (What do they know?). The aim of this paper is to demonstrate how the diagnostic perspective can be brought into focus when analysing the results of individual TIMSS items. In addition to multiple choice items, the TIMSS paper and pencil tests also consisted of free response items, some of which required a more elaborated response in form of explanations, justifications or details of calculation. In order to analyse and compare students' responses on free response items, a twodigit coding system was developed as a tool for categorisation. The coding rubrics give information about correctness, method, approaches, errors and intuitive ideas (alternative conceptions or misconceptions). The fundamental basis of the coding rubrics is simplicity, authentic studentresponse orientation and acceptable inter-rater reliability. Some TIMSS science items are studied in order to show the benefit of the coding system, in particular its potential for exploring and understanding student thinking around the world. The students' understanding of some fundamental science concepts and phenomena is discussed: The water cycle, temperature regulation of the human body, electromagnetic induction, melting and boiling, force and pressure, and force and movement. In addition, some more general and principal aspects of student understanding in science are discussed.