Issues to consider with experiments

Types of reactivity Hawthorne effects Demand characteristics Placebo effect

Ways to reduce reactivity

Experimenter bias Ways to reduce Experimenter expectancy effects

Types of validity Internal External Construct Conclusion (Statistical)

Which are these? A fire alarm goes off in the middle of your study You don’t have enough participants to show an effect in your study, according to your power analysis You want to be able to generalize your results to all Americans You’re not sure how good your measure of depression really is

Within- vs. between- participants designs Carryover effects Practice Fatigue Contrast Knowledge of study Counterbalancing Each person is their own control, more powerful

Other experimental terms Manipulation check Pilot study

Find the confound You do a study examining the effects of political orientation on attitudes toward corporal punishment. You do a study examining age effects (people who are in their 20s, 30s, 40s, 50s, 60s, and 70s) on intelligence, using a knowledge test as a measure of intelligence. You do a study of helping behavior. A man or a woman asks for help from people as they come to their cars in a dark parking lot at night.

What can you do to get rid of a potential confound? Make it an IV Make it a control variable Control for it statistically