- Variables
- Subject Characteristics
- Constants
- Variables
- Independent
- Dependent
- Moderator
- Extraneous
- Group Comparisons Research Designs
- Experimental Research Design
- X=Treatment
- O=Observation (Test)
- R=Random Assignment
- Quasi-Experimental Design
- Matching Only Design
- Counterbalanced Design
- Time-Series Design
- Causal-Comparative Design (Ex Post Facto)
- Threats to Experimental Validity
- Internal (see handout)
- External