A model of Human-Computer Interaction proposed by Donald A. Norman. This model is based on a execution-evaluation cycle which has two major stages, execution and evaluation, which can be further subdivided into further stages.

The model of interaction is as follows, where each stage is the activity of an the user:

As you can see, this model of interaction is only concerned with the user, and not the computer. Further models such as the interaction framework proposed by Abowd and Beale compensate for the lack of inclusion of the interaction of the system with the interface.