This study attempted to develop and validate a set of scales to measure ecological characteristics of environmental setting in home and preschool. Scales were developed to assess four characteristics of environmental setting: (1) accessibility, the ease with which a child can interact with his environment; (2) configuration, the function and arrangement of space in home and preschool; (3) instability, the patterned use of time periods and time-related function of spatial areas; and (4) complexity, the extent to which the environment fits the child's mental skills as well as his physical skills. Items for the scales were generated from reviews of the descriptive literature on home and parent behavior, the literature on current preschool program practices, and observations of homes and preschools made by the investigator. To establish criterion validity, a study was run to assess the degree to which the four scales discriminated among three categories of preschool programs known to differ in environmental setting as an extension of theoretical orientation on development. All of the scales were found to have suitable reliability for their intended purposes. Substantial face validity was established, but results of the validity study do not allow for judgments to be made concerning criterion validity for the scales. (Author/SB)