Field and discipline classifications were based primarily on literature searches in NASA's Astrophysical Data System (ADS) and indexes of the main journals. This information allowed fairly accurate classification of 85 to 90 percent of the sample. Place of employment was determined from the address in the AAS directory or, if only a home address was given, from the institutional affiliation given on papers published in or near the year surveyed. In what follows, people who could not be assigned fields or disciplines (NA in Table A.1 ) are not counted in computing fractions of the community. Despite maintaining AAS full membership, they probably were (1989) or are (1997) no longer active researchers publishing work in the field of astronomy. For those cases in which the committee could determine that individuals were not employed in any of the major categories, they were counted in the “other” employment location category.