In a companion paper, we proposed the well-delineated-object conjecture to describe a rational observer's behavior in a search task. We discovered two intrinsic properties to describe the performance of rational search observers: rationality in classification and location uncertainty. We proposed to use the location-known-exactly (LKE) ROC curve and the effective number of well-delineated objects or effective set size (M*) to quantify these two properties. The purpose of this paper is to develop an experimental framework to test the conjecture that was put forward in the companion paper. In particular, for each observer, we designed experiments to measure LKE ROC curve and M*, which were then used to predict the same observer's performance in other search tasks. The predictions were then compared to the experimentally measured observer performance. Our results indicate that modeling the search performance using the LKE ROC curve and M* leads to successful predictions in most cases.