The influences within the Ontario educational system perceived by teachers, department heads, and principals as affecting their evaluation policies and practices were studied. Interviews were conducted in the 1987-88 school year as part of the Ecology of Evaluation research project conducted in Ontario and British Columbia. About 50 elementary and secondary educators were interviewed in Ontario, with about half being teachers. All three levels of educators reported that factors associated with the Canadian Ministry of Education, school boards, and school policies influenced the ways in which they evaluated students. Some of the influences were identified as constraints, but many were identified as being resources for the educators and sources of practices for better recordkeeping and achievement reporting. Respondents also indicated that they received support for their evaluation efforts from their peers more often than from educators at a higher level in the same school. Support from people at a higher level was more likely to come from the district or the Ministry of Education than from within the school. Findings highlight the importance of two areas needing greater recognition: (1) a distinction that should be made between evaluation in theory and in practice; and (2) the informal network of peer support that influences evaluation practices. (SLD)