In designing the methodology for this study, Media Matters sought to employ rules for classifying guests that would be simple, easy to apply, and acceptable to readers from across the ideological spectrum. We did not attempt to ascertain whether what a particular guest said on a particular show adhered to his or her ideological profile or was critical or supportive of one party or administration. Instead, we simply coded guests by their affiliation and history. Current and former elected and administration officials, candidates, and party officials were classified as Democrat or Republican; all others were Conservative, Progressive, or a neutral category including centrists and those to whom ideology was not applicable. Rules were established for certain classes of guests that appeared frequently; for instance, active duty military personnel were coded as representing the administration in power at the time of the appearance, but retired military personnel, since they are nearly always brought on only to offer military analysis, were coded as neutral. Given that Media Matters is a progressive organization and we hypothesized (correctly, as it turned out) that conservatives have an advantage on the Sunday shows, we understood that criticism of our conclusions would be likely to come from the right. Therefore, in the few close calls we encountered, we erred on the side of classifying guests to the left. Further details on the methodology and results of the study can be found at www.mediamatters.org.