A framework for validation of the use of performance assessment in science

The assessment of learning in school science is important to the students, educators, policy makers, and the general public. Changes in curriculum and instruction in science have led to greater emphasis upon alternative modes of assessment. Most significant of these newer approaches is “performance assessment”, where students manipulate materials in experimental situations. Only recently has the development of performance assessment procedures, and the appropriate strategies for interpreting their results, received substantial research attention. In this study, educational measurement and science education perspectives are synthesized into an integrated analysis of the validity of procedures, inferences and consequences arising from the use of performance assessment. The Student Performance Component of the 1991 B.C. Science Assessment is offered as an example. A framework for the design, implementation, and interpretation of hands-on assessment in school science is presented, with validity and feasibility considered at every stage. Particular attention is given to a discussion of the influence of construct labels upon assessment design. A model for the description of performance assessment tasks is proposed. This model has the advantage of including both the science content and the science skill demands for each task. The model is then expanded to show how simultaneous representation of multiple tasks enhances the ability to ensure adequate sampling from appropriate content domains. The main conclusion of this validation inquiry is that every aspect of performance assessment in science is influenced by the perspective towards learning in science that permeates the assessment, and that this influence must be considered at all times. Recommendations are made for those carrying out practical assessments, as well as suggestions of areas that invite further research.