For undergraduate courses in Human-Factors Engineering, Human-Computer Interaction, Engineering Psychology, or Human-Factors Psychology. Offering a somewhat more psychological perspective than other human factors books on the market, this text describes the capabilities and limitations of the human operator—both physical and mental—and how these should be used to guide the design of systems with which people interact. General principles of human-system interaction and design are presented, and included are specific examples of successful and unsuccessful interactions. It links theories of human performance that underlie the principles with real-world experience, without a heavy engineering-oriented perspective.