An Insider’s Perspective on Observing Time Selection Committees

Abstract

The process of selecting the best proposals for observing time on observatories in space and on the ground is vitally important for astronomy and is generally done well, but the system has problems and can be improved. I identify four types of bias that enter the process when the oversubscription of observing time is large. The negative interaction between the large oversubscription rates and these biases should be recognized and can be mitigated. I believe that selection committees provide the most competent and least biased advice when they are given a modest number of proposals (roughly 50) covering a coherent but modest range of scientific topics, and the approximate time allocations among the committees covering the different scientific topics are driven largely by proposal pressure. There are several mechanisms for revising when necessary the allocations of observing time among the various committees.