A discussion of the role of second language proficiency assessment in the evaluation of language programs argues that for four reasons, the use of proficiency is inappropriate as a central element in evaluation. The reasons are: (1) the construct of proficiency has not been operationalized in a way that enables it to be used usefully; (2) criterion-referenced measures of achievement are of more practical utility than are statements of proficiency not tied to specific program goals; (3) regardless of the terms in which learner outcomes are to be defined, comprehensive program evaluation requires the collection, interpretation, and evaluation of data relating to a range of processes and elements operating within a particular educational context, not just learner outcomes; and (4) process data is needed to interpret outcomes data. A number of practical suggestions for program evaluation, and sample instruments, are offered. (MSE)