Process evaluation is a critical element in understanding the results of any research. Because action research is conducted by practitioners, there is a tendency to think that there is little need for process evaluation. Yet, the complexity of factors underlying most educational treatments tends to defeat all but the best memories when attempting to recall specific facts regarding the treatment. Hence, there is a clear need for process evaluation in all but the simplest of action research undertakings. In this paper, the emphasis is on fundamental techniques that would underlie the evaluation of an investigation into implementation of a curriculum intervention. Four aspects of conducting process evaluations of curriculum intervention are considered. The first aspect is defining the actual curriculum as opposed to the intended curriculum. The next aspect is considering and tracking the level of student involvement. Thirdly, the process of instruction, the use of assessment in instruction, and the relation of both to process evaluation are examined. A final consideration is tracking time by instructional element through process evaluation. Each of these aspects must be examined in a carefully implemented process evaluation, an effort that will more than repay the practitioner. (SLD)