The public demand for accountability, legislative mandates, and increased unionization of teachers have focused attention on the inadequacies of traditional teacher evaluation procedures. Attempts to design models that differentiate effective and noneffective teaching have not produced agreed-upon sets of competencies, characteristics or behaviors common to "good" teachers. A review of the research literature into teacher evaluation reveals that the major factors that impose constraints on effective teacher evaluation are: (1) teacher resistance to evaluation procedures that they perceive as arbitrary or serving only administrative purposes; (2) the lack of agreement concerning criteria on which evaluation should be based; (3) legal issues arising from fair dismissal laws, collective bargaining, and negotiations; and (4) human, conceptual, and technical skills of the evaluator which either negate or confirm the validity of the evaluation process. (Author/MJB)