Constructive interaction is a method involving two users at the same time in solving a problem. O’Malley et al. brought this method into the studies of human-computer interaction in the mid 1980’s. In this method, two subjects with comparable expertise explain their ideas and rationale behind their hypotheses to their partner. The subjects are encouraged to experiment with the studied system, and they are disturbed or interrupted only if the discussion ends. O’Malley et al. recommend this method to be used when emphasis is on understanding or developing system concepts instead of learning procedures.