Lecture 7: Intro to Experimental Method
10/19/05, 10/24/05
- Experimental Method
- Definition of an experiment
- Independent Variables
- What the "cause" is
- At minimum, 2 levels
- Situational Variables
- Task Variables
- Instructional Variables
- Controlling Extraneous Variables
- factors we’re not interested in but might cause problems
- Measuring Dependent Variables
- Manipulated vs. Subject Variables
- What is a subject variable?
- What is a manipulated variable?
- Drawing conclusions
- Some Examples
- Validity
- Statistical Conclusions
- Construct Validity
- External Validity
- Other populations
- Other Environments
- Other times
- Internal validity
- Threats to Internal Validity
- Usually due to lack of control groups or comparing non-equivalent groups
- Pre-Post Studies
- Pretest-treatment-posttest
- History confound
- How to deal with it?
- Control group
- Make it part of the study
- Maturation
- Regression to the mean
- Testing
- Instrumentation
- If the measurement tool for T1 is not the same as it is for T2
- If observers get better with practice
- Participant Problems
- Selection effects
- Attrition
- Examples
Research
Methods Page
Last updated: 10/18/05