interaction design

Resources: For People

People - what makes them tick

Norman's basic theory of human action

The world

Having even the most basic understanding of how people do things can help us design better user interfaces.

Norman's theory of basic action identifies three basic stages:

Goal formation (eg)
Execution (eg)
Evaluation (eg )

Seven stages of action

Norman expanded the theory to include 7 stages

Goal

Establish a goal

Execution

Form an intention
Specify an action sequence
Execute an action

Evaluation

Perceiving the system state
Interpret the state
Evaluating the system state with respect to the goals and intentions

Design Implications

Stage of Action	Design Question: How easiliy can the user ... ?
Form the goal	Determine the function of the product or system
Form the intention	Tell what actions are possible
Specify an action	Determine mapping from intention to action
Execute the action	Perform the action
Perceive the state of the world	Tell if the system is in the desired state
Interpret the state of the world	Determine the mapping from system state to interpretation
Evaluate the outcome	Tell what state the system is in

Gulfs of execution and evaluation

Related to the theory of action is the gulf of execution and the fulf of evaluation. These explain the gaps that exist between the user and the interface and point to how to better design an interface so that the user can cope with it.

Gulf of execution

Gulf of execution: is the distance between the user's goals and the means of achieving them through the system

When problems in the execution phase occur, the "gulf of execution" widens
Here, the distance between the users' goals and their ability to use the system increases
Some examples:

"What do I do now?"
"How do I [...]?"
"I wanted to [...], but I can't see how I would do that?"
"Do I press this?"
"Do I type this in here?"
"I'm looking for [...] but I can't find it"

Gulf of evaluation: the amount of effort required to determine the system state

When problems occur in the evaluation phase, the "gulf of execution" widens
Here, the distance between the system response and the users' goals widens
Some examples

"What happened then?"
"What did I do wrong"
User repeats the action (e.g. clicks the NEXT or SUBMIT button)

Question: think of a situation where you could use this theory to explain a problem you had with an interface you were trying to use ( eg think about ATM machines, photocopiers, dvd recorders etc)

Source: Adapted from Alexander, D. (2003) Usability and human Factors 2003 Monash Web Workshop Series viewed February 28, 2007, online<http://www.its.monash.edu.au/staff/web/slideshows/usability-humanfactors/>