Definition

1. Study of people and computing and the way they influence each other
2. Set of processes, dialogues and actions through which a human user employs and interacts with a computer
3. Discipline concerned with the design, evaluation, and implementation of interactive comuting systems for human use

Definition number 3 is the best and most coherent one.

User Productivity

User productivity = Functionality * Usability. If either is zero, the system is useless.

Factors influencing user productivity:

• Types (complex/simple, real-time/batch) and number of task
• Characteristics of users (ability, experience, etc)
• Work environment (distractions, etc)
• Training and documentation