Evaluation is a bit like listening. As listening is commonly labeled the most neglected language art, evaluation is the most neglected component of inservice education. If it is included, the evaluation that's done tends to be one-dimensional. That is, it is usually summative (at the conclusion) and product-oriented (tangible results) instead of formative and process-oriented. Evaluation--if it is to be a worthwhile part of inservice or staff development--needs upgrading.
Vacca, J. L. (1983). Upgrading Evaluation of Inservice Delivery. Reading Horizons, 23 (2). Retrieved from https://scholarworks.wmich.edu/reading_horizons/vol23/iss2/5