Near the end of the article Claudia Kotchka talks about prototype workshops...
"Participants get scared using such rough prototypes to elicit
consumer feedback at the beginning, but they are won over when they
see the benefits of co-creation," says Kotchka. "We have found that
the more finished a prototype is, the less feedback people will give
you. When you give prospective users something half-finished, they
think you don't know the answer. They know you need their help—and
really open up."
She probably should have given some credit to Bill Buxton regarding
the notion of using form and polish to project openness and encourage
input and exploration.