This excellent collection provides the reader with a comprehensive coverage of findings and theories about how people encode and summarize frequency information. While it is a smorgasbord of self-contained chapters with little cross-referencing (or elaboration of disagreements), the high quality of the vast majority of these chapters yields a cognitive feast. They are written by eminent researchers who have opted to present both recent results and summaries of their most important work - certainly not the feared secondary idea or paper submitted because it would be easier to publish in an edited volume than in critically peer reviewed journal.