How to assess user experience

Thu 7th March Tobias Komischke

Aims:

• Suitability for task (e.g. Amazon = 15 tabs to get to the input box!)
• Self-descriptive
• Controllability
• Conform to user expectations
• Error tolerance
• Suitability for individualisation
• Suitability for learning

Example of proving UI was improved using a radar chart:



Avoid:

• Non-standard UI controls
• Inconsistency
• No perceived affordance
• No feedback
• Bad error messages
• No default values and bad cursor focus
• Dumping users right in (completely empty OR really full)
• No workflow support

Other UI considerations

 

Screen clutter	Aesthetics / human factors - clutter limits the brains ability to process info
Text legibility	Character sizes - well known optimum + minimum text sizes for handhelds / monitors / projection walls. Hard to do for different form factors
Text orientation	Don't use Marquee Rotated right slightly better than left. Horizontal is best
Colour contrast	Tools available on the web Colour blind = 8% of men, 0.43% of women.  Mostly red/green RAGs: Use both colour / shape and icon
Text alignment in menus	Left align is best (for English) In forms: align text next to the control (proved using eye tracking) top align is also ok (benefit is language translation when the text size will vary) Bad = bottom right or in the input box (info has gone once input + watermarked text is hard to read + presume it's already been input)
Visual structure and flow	Grid structure and flow Improve readability, quicker learning Standardisation reduces design Add grid lines to measure conformance
Orientation	Where am IWhere have I come from What's next
Icon quality	Concreteness = resemblance to real world counterpart Complexity = Richness of details depicted (want low) Semantic Distance (want low)
Data visualisation	Bar charts are best Volume control worst (humans can't spot area changes)
Visual attention	Where do people look? Eye tracking is costly OR Saliency modelling - use website "Feng GUI" to simulate where people will look first.  1 free heat map per day.
Usability testing	Real users Real tasks Prototypes + real products Thinking aloud Qualitative + quantative data 7/8 people will find 80% of usability problems.  Diminishing returns. Trend towards remote UI testing - easier + better tooling these days