Chapter 11 Flashcards
1
Q
What are six threats to internal validity in one-group pretest/posttest designs?
A
- maturation threat
- instrumentation threat
- testing threat
- history threat
- attrition threat
- regression threat
2
Q
What are three threats to internal validity in any study?
A
Observer bias, demand characteristics and placebo effect.
3
Q
What are two reasons for a false null effect (type II error)?
A
Not enough variability between levels or too much variability within levels.
4
Q
What are two types of not having enough variability between levels?
A
Weak manipulations and insensitive measures (ceiling/floor effects).
5
Q
What are three types of noise (too much within-group variability)?
A
Measurement error, individual differences and situation noise.
6
Q
What is power?
A
Likelihood that a study will give a significant result when the independent variable really has an effect.
