DEVELOPING A CALABRATED PROGRESS VARIBLE FOR THE PARTICLE NATURE OF MATTER The Investigating and Questioning our World through Science and

Technology (IQWST) curriculum takes the approach of building students’ ideas over time. This approach uses construct maps, a visual representation of progress variables, to structure learning activities and assess student learning. This paper presents the evaluation of the assessment items developed for the 6th grade chemistry unit in relation to a construct map developed for the particle model of matter. Ninety-two 7th grade students in a Midwestern school district participated in the study. Data sources include two alternate forms of the test and audiotaped interviews of four students. Analysis of this data will be used to evaluate the assessment items and the construct map