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Flashcards in P.O.E.T Deck (17)
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what is an affordance?

The affordances of an object are how it can be used (how it can be perceived to be used)


What is a perceived affordance? Give an example.

perceived affordances are about how perceptions of an object in a simulated environment operates.

A computer mouse affords clicking, scrolling, pulling, pushing etc.


How do we learn conventions?

we learn conventions through:
-clear consistent fundamental design model
-appropriate mappings
-action feedback loop


What are the pieces of Norman's 'System Image'? and their roles?



How do affordances differ from purposes?

-purposes come from the designer
-affordances are understood by the user


Why are labels not considered part of the UI?

-UI is what the users connect to, users do not connect to labels
-labels/instructions/manuals etc are part of the system image and help users to construct a conceptual model


How do labels differ from affordances?

-affordances are actual or perceived properties of an object
-labels are not properties of an object


Why is visibility important?

-The correct parts must be visible, and they must convey the correct message
-visibility allows for affordances to be perceived.


Why can too much visibility be a bad thing?

Too much visibility can be a bad thing. Consider the fancy washing machine with too many settings (discourages people from using it, discourages user from attempting to learn all the functions)


What is a conceptual model?

A conceptual model is what the interface tells you about how a system functions.


What is a mapping?

a mapping is a clue that relates an interface to an action


What is the difference between mapping vs natural mapping?

Mapping implies a relationship between an interface and an action. A natural mapping will use physical analogies and cultural tendencies to create that implication.


What is "feedback" in terms of the "system model"

Feedback is sending a response back to the user about what action has actually been accomplished


What are the 7 principles for simplifying tasks?

1- Use knowledge in the world(in the system) and knowledge in the head(prior knowledge of the user)
2- Simplify the structure of tasks
3- Make things visible
4- Get the mappings right
5- Explore the power of constraints
6- Design for error
7- Standardize


What are some tradeoffs between knowledge in the world vs knowledge in the head?

-world: easily retrievable
-head: not easily retrievable, requires search or reminding

-world: learning not required, instead interpretation is substituted
-requires learning which can have considerable overhead

Efficiency of use:
-world: tends to be slowed up by the need to find and interpret external information
-head: can be very efficient

Ease of use at first encounter:
-world: high
-head: low


What are the "gulfs" that the user must bridge when using a system?

Gulf of execution:
-user forms intention, user specifies action, user performs interface action

Gulf of evaluation:
-user evaluates, user interprets display, system displays


What are the types of constraints?

-physical constraints: are inherent
-logical constraints: use reason to determine choices
- cultural constraints: a learned convention