Introduction to Action, Evaluation, Linking the Info Proc Model to Design Flashcards
What are the 7 stages of action (Norman)
- Forming the goal
- Forming the intention
- Specifying an action
- Executing the action
- Perceiving the state of the world
- Interpreting the state of the world
- Evaluating the outcome
What are the stages of Execution (Norman)
Thus, formulation of stages of execution:-
Start at the top with the goal, the state that is to be achieved:
1) The goal is translated into an intention to do some action.
2) The intention must be translated into a set of internal commands, an action sequence that can be performed to satisfy the intention.
3) The action sequence is still a mutual even: nothing happens until it is executed, performed upon the world.
What is Evaluation, according to Norman
Evaluation formally means to examine and calculate. Norman explains that after turning on the light, we evaluate if it is actually turned on. A careful judgement is then passed on how the light has affected our world i.e. the room in which the person is sitting on the armchair while reading a book.
What is Execution, according to Norman.
Execution formally means to perform or do something. Norman explains that a person sitting on an armchair while reading a book at dusk, might need more light when it becomes dimmer and dimmer. To do that, he needs to switch on the button of a lamp i.e. get more light (the goal). To do this, one must need to specify on how to move one’s body, how to stretch to reach the light switch and how to extend one’s finger to push the button. The goal has to be translated into an intention, which in turn has to be made into an action sequence.
What are the stages of Evaluation (Norman)
The formulation of the stages of evaluation can be described as:
1) Evaluation starts with our perception of the world.
2) This perception must then be interpreted according to our expectations.
3) Then it is compared (evaluated) with respect to both our intentions and our goals.
What is the Gulf of Execution?
The difference between the intentions and the allowable actions is the Gulf of execution.
“Consider the movie projector example: one problem resulted from the Gulf of Execution. The person wanted to set up the projector. Ideally, this would be a simple thing to do. But no, a long, complex sequence was required. It wasn’t all clear what actions had to be done to accomplish the intentions of setting up the projector and showing the film.”
What is the Gulf of Evaluation?
The Gulf of evaluation reflects the amount of effort that the person must exert to interpret the physical state of the system and to determine how well the expectations and intentions have been met.
“In the movie projector example there was also a problem with the Gulf of Evaluation. Even when the film was in the projector, it was difficult to tell if it had been threaded correctly.”
How is the Gulf of Execution and the Gulf of Evaluation bridged?
1) Have the system provide information about itself and its functions in a perceptible, meaningful way
2) Make sure that desired actions are clear and supported
What is Norman’s definition of Affordance?
An affordance is a quality of an object, or an environment, which allows an individual to perform an action.
- Have perceived properties that may or may not exist
- Have suggestions or clues about how to use these properties
- Can make an action easy or difficult
For example, a knob affords twisting, and perhaps pushing, while a cord affords pulling.
What is affordance dependent on?
1) Expereince
2) Knowledge
3) Culture of the actor
What does affordance determine in design?
Affordance of an object determines, naturally how it can be used. Just by looking at an object, a user should know how to use it
What is preceived affordance?
The perceived properties of the object that suggest how one could use it
(Turn or push to activate????)
What are two principles to bridge the gulf of affordance?
1) Provide a good conceptual model.
2) Reduce gulfs of evaluation and execution.
3) Make things visible to indicate what action can be taken. (example: menus vs. command lines; state of the system like amber light on cruise control).
What do conceptual models help the user do?
A conceptual model is the conceptualization of a target system held by experts. Helps people understand the relationship between controls, their impact on system state, and their goals
What are the principles of good feedback?
Feedback has to be immediate, obvious reactino to each action
(Why many web sites now tell you to “only click this button once” – they aren’t giving immediate feedback. This is why their might not be feedback on your side. They know this delay announces people, which will cause them to click the button several times.)
