Abstract Computer-based assessment of problem solving is motivated by the need for educational assessments that are valid and efficient. Based on a recent revision of Bloom's taxonomy (Anderson et al., 2001, A taxonomy for learning, teaching, and assessing: a revision of Bloom's taxonomy of educational objectives. New York: Longman), assessment items should require applying a particular cognitive process to a particular type of knowledge. There are 19 types of cognitive processes that can be classified into six major categories: remember, understand, apply, analyze, evaluate, and create. There are four major categories of knowledge: factual, conceptual, procedural, and metacognitive. Examples of computer-based assessments of problem-solving are provided based on the evaluation of the cognitive consequences of children's participation in an after-school computer club.