CHP. 13 - Quasi-Experiments & Small N-Design Flashcards
Quasi-Design
Subjects choose which group they’re in
- Use when full random assignment isn’t possible
Non-Equivalent Control Group Pre-Test/Post-Test Design
No random assignment & participants tested both before & after some intervention
Interrupted Time-Series Design
Researchers take full advantage of an already scheduled event or new policy/regulation
- ex. food break
Can quasi-experiments be trusted?
Main concern is internal validity
Selection effects
- Solution: matched group & wait-list design
Benefits of quasi-experiments
- Takes advantage of real-world opportunities
- Real world setting may enhance external validity
- Could be more ethical
Small N Studies
Each participant is treated as a separate experiment
- often a repeated measures design
Disadvantages of Small-N
Low external validity
Stable Baseline Design
Study in which researchers observes behavior for extended baseline before treatment/intervention
- help address maturation & regression threats
Multiple Baseline Design
Researchers stagger the introduction of intervention across variety of contexts times/situations
Reversal Design
Researchers observe a problem behavior both with & without the treatment
- baseline -> treatment -> reversal -> treatment
Validity of Small-N
Can have good internal validity
