The user knows best and is the only guide to the designer

The designer's role is to translate the users’ needs and goals into a design solution.

Focuses on the behavior surrounding particular tasks

Users still play a significant role but it is their behavior rather than their goals and needs that are important.

A structured, rigorous, and holistic design approach that focuses on context and is particularly appropriate for complex problems.

The system are the center of attention while the users’ role is to set the goals of the system

Different from the other three approaches because it relies solely on the experience and creative flair of a designer

In this approach the users’ role is to validate ideas generated by the designer, and users are not involved during the design process itself.

Directly studying cognitive, behavioral, anthropomorphic & attitudinal characteristics.

Empirical measurement: users’ reactions and performance to scenarios, manuals, simulations & prototypes are observed, recorded and analyzed.

One of the requirements that inform the designer what the system should do.

An approach to ethnographic study where user is expert, designer is apprentice.