Do students achieve the desired learning goals using open-book formative assessments?

The present study aimed to examine whether medical students benefit from an open-book online formative assessment as a preparation for a practical course. A between-subjects experimental design was used: participants - a whole cohort of second-year medical students (N=232) - were randomly assigned to either a formative assessment that covered the topic of a subsequent practical course (treatment condition) or a formative assessment that did not cover the topic of the subsequent course (control condition). Course-script-knowledge, as well as additional in-depth-knowledge, was assessed. Students in the treatment condition had better course-script knowledge, both at the beginning, t = 4.96, p < .01, d = 0.72., and in the end of the practical course , t = 4.80, p < .01, d = 0.68. Analyses of covariance show that this effect is stronger for those students who understood the feedback that was presented within the formative assessment, F =10.17, p