What are the goals of theory? • To understand • To predict • To influence • To control
To build a theory…... • Categorization • What information is relevant? • What information can you ignore? • Description is never just description
Correlation is not causality Statistics explain nothing If we understand the process, we can understand the conditions under which it will happen.
Theories do: • Explanation • Prediction • Prescription
How do you know if a theory is ‘valid’? Testing Evaluation Faith = BAD
The Classical Physics Model • Fundamental determinants of phenomenon • Small number of variables • Clearly defined relationships between them • Measurable! • Parsimony is a good thing
The Social Science Challenge • Equifinality and Multifinality • Hard to measure variables • Sets of theories or contingent generalizations require boundary conditions: when do they apply and when don’t they? • Progress is about moving from probabilistic statements to contingent statements
So what’s a ‘good’ theory? • Accuracy • Parsimony • Causality • Heuristic Value