As a new program is developed, information must be collected to identify weaknesses, to guide the staff in the revision process, and to formulate decision-making procedures, i.e., formative evaluation techniques are essential. A set of criteria for the information needed in formative evaluation is set-up and a practical strategy for meeting these criteria is described. It is suggested that the ideas of achievement monitoring, time series experimental design, and item sampling be jointly applied. Such a procedure has been utilized for a formative evaluation of a new sixth grade arithmetic program. This evaluation, including suggestions for its improvement, is described in detail. An example Patterns in Arithmetic test with item profiles over time, is appended. (DG)