Validity in teacher assessment. An exploration of the judgement processes of assessors
Assessment of teaching is currently becoming more and more common practice. As such assessment is generally based on complex, qualitative data from multiple sources (e.g., lesson plans, video-taped lessons, written reflections of the teacher on his or her performance), the overall quality of the assessment depends heavily on the judgement processes of assessors. Assessors have the essential tasks of consideration of evidence from separate sources and combination of this evidence to attain a coherent overall judgement.
- Mirjam Nijveldt
- 16 January 2008
- Fulltext in Leiden University Repository
In the current research, the judgement processes of twenty-four assessors were analysed. All assessors judged the same student teacher, using a specific assessment procedure. The results of the research provide insight in the potential threats to the validity of the judgement process and of the assessment overall. An example of such a threat is a tendency to consider mainly confirmatory evidence for initial interpretations as opposed to also considering counterevidence or alternative interpretations. Assessors are not always aware of such threats, and even when they are, the do not always know how to overcome these threats. The results of this research have implications for ensuring the quality of assessment and for the preparation of assessors. Assessor training should explicitly be aimed at increasing awareness of the relevant judgement processes, specific threats to the quality of these processes and potential succesful strategies to overcome these threats.