Q&A: Order in the Course: Five Principles of Meaningful Interaction Sequencing
taught by: Robert O’Connell
Five principles inhere in meaningful interaction sequencing. These principles are often overlooked by UI designers, but ignoring them impacts people who rely on focus navigation (keyboard, touch swiping, voice command, screen reader navigation). The five essentials of interaction sequencing are:
* Name must lead in name-value pairing
* Parent must lead in parent-child sequencing
* Action must precede in action-consequence sequencing
* Containers must precede contents ambidirectionally
* Component options should be foregoable
Meaningful sequence applies to both static and dynamic content, whose reading order should be logical and programmatically discernible. Typically, for English readers, screen reader reading order should match visual reading order: left to right, top to bottom, section by section, event by event.
When digital designers present reading or action flows that subvert innate human cognitive processes of logic or behavior, the reaction is: disorientation, re-exploration, re-interpretation, re-orientation. The cost of disorientation may be lower for visual readers than for assistive technology users, but it's a cost to be avoided.
Five principles inherent in interaction design apply to meaningful relationships:
- Name must lead in name-value pairing: the name of a record must precede its associated values in the readable code order.
- Parent must lead in parent-child sequencing: each parent element must precede its child element in the readable code order.
- Action must precede in action-consequence sequencing: a control that affects content must precede in readable code order the content it affects.
- Containers must precede contents ambidirectionally: items groups in nested containers must allow navigation by container layer.
- Component options should be foregoable: a component that has options for selection should not require interacting with those options.
- Ability to explain how humans derive meaning from content sequencing.
- Ability to diagnose common design dis-orders.
- Ability to design digital reading and interaction flows with greater awareness of cognitive logic.