Restructuring of electric power markets is proceeding across the United States and in many other nations around the world. The performance of these markets will influence everything from the prices faced by consumers to the reliability of the systems. The challenges of these changes present many important areas for research. For much of the northeastern United States, restructuring proposals include, at least for the short term, the formation of a single-sided auction mechanism for the wholesale market. This research uses experimental methods to analyze how these markets may function. In the experiments, the two basic uniform price auction rules are tested under three different market sizes. Early experimental results suggest the commonly proposed last-accepted-offer auction works well, but market power could be a real concern.