Current methods of assessing nominal scale response agreement between two raters allow each rater to make only a single response per object. When raters are uncertain in their responses, such methods can underestimate the extent to which agreement exists in the range of possible classifications envisaged by raters for each object. Accordingly, an exact unweighted test procedure is developed for the analysis of nominal scale response agreement in the event of rater uncertainty. A rater who is undecided about the appropriate category label for an object is allowed to assign more than one category label to that object. The researcher can choose an operational definition of agreement under uncertainty which is appropriate to the goal of a study. The approach, which is based on the combinatorial technique of rook methodology, supplies the exact null distribution of the amount of agreement between two raters who may make multiple responses per object. The present findings also provide, as a special case, exact results for the unweighted single‐response approac