1. You Can’t Play 20 Questions with Nature and Win
Alan Newell (1973)

2. Progress in Psychology
New phenomena
Experimental techniques
Elegant theories
But what do they add up to?

3. 20 Questions Parsing nature into binary oppositions
Never really answered
Elaboration of theories on both sides
Little cumulative progress
Lack of integration

4. Strategy and Flexibility
Mind capable of many things
Role of task & instructions?
No models of “control structure”
Needed for integration

5. Complete Processing Models
Model whole task, from instructions and sensation to motor output
Model all aspects of one complex task
Class inclusion
Mental arithmetic
Chess
Control structure ties model together
Best candidate: production system