This study examines the content and nature of Maine's locally devised definitions of master teachers from three perspectives: (1) the criteria which have been proposed by 16 local committees; (2) the acceptability of such criteria to a broad cross section of Maine teachers; and (3) the comparability of what has been proposed to what appears acceptable. The 16 locally developed lists and the criteria which comprise them were examined and compared on the basis of: (1) a conceptual framework derived from categories used in the Tennessee Career Ladder Program; and (2) types of criteria used in research on teaching. The criteria content were then assessed through a survey of a random sample of Maine teachers; the analysis of the survey provided information about the content and nature of criteria which are most likely to be accepted or rejected by a broad cross section of Maine teachers. The final analysis explores the congruence between the criteria preferences of local committees and the criteria preferences of Maine teachers. Based on this analysis, implications of the study which should help the designers of future criteria lists are noted. (18 references) (JD)