Failure, Success, and Motivation

(This post the fourth in a series commenting on Kathy Sierra's presentation about creating passionate users.) 

As a professional development facilitator, curriculum designer, mentor, or teacher, how do you motivate your "users." One of Kathy's points is to make the product they will actually use. She suggests to make the right things easy for people and the wrong things hard. Kathy was presenting in a certain style that makes it hard to get beyond the superficial, but that seems too simplistic. If we are aiming for intrinsic motivation, one element that seems extremely important is finding the right balance between failure and success. Making things too easy or too hard leads to frustration or disinterest. When you have learners (kids or adults) that all come in knowing different things and having had different experiences, how do you design a one-fits all that will balance failure and success?

Scientific American recently had an article related to this conundrum. The article presented findings from a study that found learning becomes better if conditions are arranged so that students make errors. How many of us have created learning opportunities designed to avoid the problems and pitfalls students might encounter? 

A couple of other related resources:
On His Team, Would You Be a Solvent, or the Glue?
Famous Failures
Failure – The Secret to Success
F Is For Fail
Zone of Proximal Development