Capabilities of Humans

Gestalt More than the sum of its parts

Gestalt German word for form/shape/likeness Proximity objects near each other appear as a group once defined as a group, additional ‘group’ characteristics can be made / assumed Look at keynote’s tool bar:

Emergence

Multistable perception Ambiguous perception “Stably” perceive multiple things The 3D cube drawing Flashing lights moving 1 direction or the other

Invariance Consistently perceived (invariant) Mind recognizes the object despite variations in translation or even shape

Similarity

A clue into a known mental model Mimics similar characteristics of the mental model User knows by relationship the characteristics Cut, Copy, Paste Trash or Recycling Bin The Desktop Online “Shopping Cart” Metaphors

A predictive model of the behavior of something Metaphors exploit user’s mental models Expectations are based on these Users will apply their mental models regardless Know your user base Mental Model

Symmetry Positioning (translational) Within shapes repeating pattern within the shape mirror images (reflection) [ ][ ][ ][ ][ ] On a larger more abstract view; “balance”

The natural “flow” Alignment Outlines Misalignment makes something look out of order “odd one out” is useful to exploit Continuity

Exploit the minds shape recognition Graphic design uses not much on so much for GUI Pie Menu Enclosure being same concept and more common in GUIs (edit handles on a selected item) Closure

Memory 7±2

Users don’t want to memorize Web surfers are even worse “Chunking” Memory Aids keyboard short cuts, bookmarks, icons, symbols File path, Bread Crumbs, Domain Names, File Names 7±2

Time Sensory memory instant; subconscious or below that Short-term memory 30 sec - 2 min Long-term memory not reliable, easily manipulated often subconscious in nature; negatives & farce are true

Recall puts work on the user memorization Recognition helps the user Figure out the mental model to apply Jogs their memory to Recall or provides the information Exploits their working knowledge Recognition vs Recall

Interruptions / distractions < 0.1 sec = “instantaneous” < 1.0 sec = noticed, but continues > 10 sec = interrupted, “where did my glasses go?” Web users frequently get interrupted…

Perceived Affordance Intuitive

A quality that makes it easy to identify the functionalities of an interface Combines the previous topics to let users “intuitively” operate something Light switches placed relative to the lights they control Door handles positioned closer to the open side “The Design of Everyday Things” (mentioned in the syllabus)

rely on recognition instead of recall chunk info don’t make them remember stuff Consider your Target Demographic’s mental models Provide memory aids and visual cues Provide FEEDBACK to the user Conclusion