Effects of environmental enhancements on the participation of 21 preschoolers at a prewriting table during free-choice activities were examined during one school year. A reversal experimental design compared three cumulatively richer enhancements. Enhancements were: (1) two skill levels of materials; (2) two skill levels of materials with "prompts to attend the table" directed to six children who had low Brigance K and I Screen scores; and (3) two skill levels of materials, prompts, and teacher presence at the table. Data collected on a time-sampling basis showed that in comparison to baselines, voluntary and constructive participation at the prewriting table increased to significantly higher levels as the enhancements intensified, even though six other free-choice classroom learning centers were simultaneously offered. Prior to implementation of the procedures, midway, and at the end of the study, children were tested on two subtests of the Brigance K and I Screen: (1) prints personal data; and (2) visual motor skills. The results indicated that Brigance scores increased. (RH)