(Experimental and Quasi-Experimental)
The primary use of the classic experimental design
Cause-effect relationship
Three conditions that must be met in order to establish a cause-effect relationship
1. Timing 2. Association 3. Eliminate Alternative Explanations
Four components of the classic experimental design
1. Intervention 2. Exp / Control 3. Pre / Post test 4. Random Assignment
Two variations on the experimental design
1) Post-test only experimental design
2) Two “treatments”
Differences between The quasi-experimental design and the experimental design
No Random Assignment
Advantages of the experimental design -- Flaw in a quasi-experimental design:
Pre-existing group differences
Fix for Flaw in a quasi-experimental design: Solution -- Utilize matching of subjects.
Factors that give rise to / constitute a threat of "alternative explanations" in research
Selection Bias:
History:
Maturation:
Attrition (Subject Mortality):
Testing Bias:
Instrumentation:
Reactivity:
Quiz 2 is (Coming Up Quick) , what to do to prepare:
2. Download Study-Guide for Quiz 2 (printed copy is contraband -- create your own hand written copy)
3. Read “Knowledge-Base Bivariate Frequency Distributions”
4. Accomplish “Homework: Bivariate Frequency Distributions”
6. Accomplish your reference list to turn in (hard copy) quiz day.