External validity and generalizability

Threats to external validity

Common sampling issues

-EX college students used as a convinience sample

- selection bias

WEIRD samples

Western, Educated, Industrialized, Rich, Democratic

Voluntary participation

Fundamentally different from those who don't volunteer

Online research

Convenient, fast, and cheap; but up to 25%are suspicious/fraudulent

Generalizing across methods

- settings: lab vs field

- researchers/experiements: people may behave differently with different experimenters

- operations: many ways to define/operationalize constructs

- designs: observe vs experiment, btwn vs within, cross sectional vs longitudinal

Synthesizing conflicting information

Look at several different sources and consider what each source is and is not telling you

Implicit association test (IAT)

Captures unconscious evaluations and automatic reactions to stimuli

- attitude toward something without directly reporting on it

- measures response time