This relationship is termed 'niche.' Interviews were conducted with 312 prisoners concerning the attributes of prison settings. The results suggest that prisoners with different social, cultural, and personal histories express different environmental concerns in prison and that particular configurations of prison work, program, and special living assignments are likely to be reported as 'niches' by prisoners than are others. While some classes of settings are disproportionately reported as stressful or as settings which facilitate access to contraband or power, other settings stand out as ameliorative. A typing of these perceptions, including the personal (environmental concern) and setting (physical characteristics) components of each, was performed. In addition, prisoner perceptions of several typical and atypical formal ameliorative prison settings were explored. These included a protection company; an elderly and handicapped unit; a unit for young, white prisoners; and a special unit for the emotionally disturbed. Case portraits of these units include descriptions of the settings, categorizations and typing of the positive and negative features of the settings, and population profiles. The efficacy of such settings in resolving prison problems and trade-offs which occur when prisoners are placed in them are discussed. Finally, strategies for the reduction of prison stress are reviewed. Sample interview responses, data tables, and footnotes with references are provided. Appendixes contain interview coding instructions; subenvironment, random, and formal-niche interview schedules; and information on missing data and on variable coding and classification. (Author abstract modified.)