Assessing and fostering students' scientific literacy in doing comparative investigation tasks

In this article, we describe relevant criteria for designing hands-on tasks used to assess and foster student's performance in doing science. Comparative investigation tasks have been chosen as an exemplary form of doing science and can be defined as tasks where two or more objects are compared on some attribute while other variables are being controlled. Different content and performance standards to be fostered here, have been postulated a priori using a competence model. 418 students (between 12 and 15 years old) had to solve a validated performance assessment test (two tasks per student, using the same blue-print for every task) and their written protocols were analyzed with a standardized coding manual. The same learning hierarchy along the postulated standards could be elicited in every task. The interrater-reliabilities lie in between an acceptable and very good range. The results of this study may help designing and evaluating learning environments that help teachers monitoring and fostering their students Q expertise in doing science.