Psychological studies of human-computer interactions have focused, for the most part, on attempts to understand the nature of human cognition and learning. Some of the issues that are frequently discussed in the formulation of these studies are:

The nature of memory and     mental structures	Learning and problem     solving strategies
The nature of conscious and     unconscious attention	The role of language     in cognition
Response time & time to learn	Encoding processes
The nature of errors	"Gulfs of understanding"