Chapter 13 - Quasi Experiments

Question 1

define quasi experiments

Answer 1

• resemble true experiements
• researcher does not have full experiment control
• participants are not randomly assigned
• researcher tries to select two plus groups that only differ on the IV (very hard to do)
• very vulnerable to internal validity
• best to do when something isunethical to manipulate, when wanting better external validity

Question 2

how are correlational and quasi-experiments similar?

Answer 2

similiar: both compare two or more levels of one variable to repdcit another, neither use random assignment, neither manipulate variables

different: correlational are for finding association between variables, quasi is to enhance internal validity and give some evidanence for causal claims

Question 3

what are the threats to quasi-experiments?

Answer 3

• selection effects
• design confounds
• maturation
• history
• regression to the mean
• attrition
• testing and instrumentation
• observer bias
• demand characteristic
• placebo effects