Micah Altman¿is¿Director of Research¿at the¿Program on Information Science¿for the MIT Libraries. He has authored more than seventy articles, a half-dozen open-source software packages, and several books and monographs correcting computational errors in the social sciences. Michael P. McDonald is Associate Professor of¿Political Science at the University of Florida¿and a Non-Resident Senior Fellow at the¿Brookings Institution.¿He is a coprincipal investigator on the¿Public Mapping Project. Widely published in scholarly journals and law reviews, he is coauthor with Micah Altman and Jeff Gill of Numerical Issues in Statistical Computing for the Social Scientist.