Triggers
Addressed in Saffer, chapter 2
Examples of manual triggers (user actions)
- Clicking a link
- Selecting an item from a menu
- Slide or dial
- Swipe on a touch screen
Issues
- Visibility
- Granularity of analysis
- Associating control with goal
Visibility
From most discoverable to least (adapted from Saffer, p. 31)
- Moving/flashing object
- Object with affordance and label (e.g. labeled button)
- Object with label, including labeled icon
- Just an object, such as an icon
- Just a label, such as a link without any affordances
- Invisible trigger
Other guidelines
- Avoid modes: trigger should perform the same action every time
- Bring data forward: provide examples before trigger is initiated
- Follow accepted affordances
Discussion questions
- Which labels help a user associate a goal with a control? Text or icons?
- Why make some controls less discoverable?
- How do you select good labels?
- What are examples of system triggers?