Adults who had no experience in the area of mental retardation viewed slides of residential settings, five providing housing for people with mental retardation, and rated their "home-likeness" (1 = home-like, 5 = institutional). Of 55 two-way comparisons, the mean home-likeness ratings of 48 such pairs differed significantly from one another. A .98 log-linear correlation was found between number of residents in a given facility and institutional ratings. Of 26 features of living rooms studied in detail, furniture position, lighting type, and lighting flexibility were highly correlated with home-likeness, whereas building code-specific features and seating type were minimally related to home-likeness.