Goals and Objective functions

"Prototyping is a strategy for efficiently dealing with things that are hard to predict."

Different types of unknown stuff:

  known unknown   - I am aware that x is unknown variable, I know it exists.
  unknown unknown   - I wasn´t even aware that x is a variable

Prototyping helps you to reveal the unknown unknowns.

Often people have  AN  idea and only  ONE  deign. When they need to argue for their design they end up losing the fight because they do not have so many argument speaking for them.

In one way or another you have to push your design through challenge and therefore it is more convenient to think about objective functions. What will this design achieve? Why is it so good? What makes it valuable?

Users do not know which alternatives a design could have. Its the same if you ask a user what kind of tools he would like to have - he doen´t know. Therefore you as a designer need to present more than one design that the user would have the information and could answer your quest
ions through comparison. Is A better than B ? Rather then asking is A good?

User then can answer you: I like part of A and part of B because ..

-----------------------------------------------------------