This paper presents a variety of ways in which the effectiveness of four divergence thinkLets used to aid creative solution generation in a group support system environment can be measured and compared. A thinkLet is a codified facilitation technique that can be used to support a group collaboration process. In the first thinkLet, free brainstorming, four-member groups worked on their own without any form of external interaction. In the three subsequent thinkLets, the group interaction was "directed" by a facilitator who provided carefully constructed stimuli to similar four-member groups at specific timed intervals. The only difference between the directed thinkLets was the specific ordering of the stimuli set. A number of useful measurements that may be made during the course of comparing the relative effectiveness of these creativity thinkLets are discussed and compared within the context of a theoretical model. The differences among the various thinkLets are then used to offer advice for practitioners.