NNG of computerskills - seems very appropriate for coga

https://www.nngroup.com/articles/computer-skill-levels

What Most Users Can Do

If you want to target a broad consumer audience, it’s safest to assume that
users’ skills are those specified for level 1. (But, remember that 14% of
adults have even poorer skills, even disregarding the many who can’t use a
computer at all.)

To recap, level 1 skills are:

   - Little or no navigation required to access the information or commands
   required to solve the problem
   - Few steps and a minimal number of operators
   - Problem resolution requiring the respondent to apply explicit criteria
   only (no implicit criteria)
   - Few monitoring demands (e.g., having to check one’s progress toward
   the goal)
   - Identifying content and operators done through simple match (no
   transformation or inferences needed)
   - No need to contrast or integrate information

Anything more complicated, and your design can only be used by people with
skills at level 2 or 3, meaning that you’re down to serving 31% of the
population in the United States, 35% in Japan and the UK, 37% in Canada and
Singapore, and 38% in Northern Europe and Australia. Again, the
international variations don’t matter much relative to the big-picture
conclusion: *keep it extremely simple, or two thirds of the population
can’t use your design*.

(Learn more about the cognitive skills of normal people in our full-day
course The Human Mind and Usability
<https://www.nngroup.com/courses/human-mind/>.)


Steve Lee
OpenDirective http://opendirective.com