CS 66-460
Introduction to Graphical Human Machine Interfaces

The Psychology of Everyday Actions


Instructor: G. Bowden Wise
Rensselaer Polytechnic Institute
Spring 1997

Falsely Blaming Yourself

People Will Make Errors

Norman's Credo About Errors

Misconceptions of Everyday Life

Where To Place the Blame?

When Things Go Well


The Nature of Human Thought and Explanation

Norman's Seven Stages of Action

  1. Forming the goal.


  2. Forming the intention.
  3. Specifying an action.
  4. Executing the action.


  5. Perceiving the states of the world.
  6. Interpreting the state of the world.
  7. Evaluating the outcome.

The Seven Stages as an Approximate Model

The Stages of User Activities When Performing a Task

Opportunistic Actions

A Typical Task: Improving a Business Letter

The Gulf of Execution

Refers to how well the system/device enables a person to perform the intended actions directly without extra effort.

The Gulf of Evaluation

Reflects the amount of effort a person must exert to interpret the physical state of the system and to determine how well the expectations and intentions have been met.

Bridging the Gulfs

The Seven Stages as a Design Aid

Leads Back to Our Design Principles

Bowden Wise
Wed Feb 12 12:36:09 EST 1997