Bias in internal validity Flashcards
Bias in internal validity (9)
a) Selection
b) History
c) Maturation
d) Testing effect
e) Instrumentation
f) Regression to the mean
g) Mortality
h) Demand characteristics
i) Experimenter bias
Selection
a) Groups are not equivalent at the start of the experiment
b) Participant variability
In which design methods do selection bias occur?
Independent measures design
History
Outside events that happen to participants in the course of the experiment
In which experiments do selection bias occur?
Lengthy experiments
How are history bias controlled?
a) Elimination of extraneous variables
b) Constancy of variables
Maturation
Natural developmental processes such as fatigue or simply growth
How are maturation bias controlled?
Using a controlled group
Testing effect
The first measurement of the DV may affect the second measurement
In which design methods do selection bias occur?
Repeated measures
How are testing effect bias controlled?
Use a control group
Instrumentation
The instrument measuring the DV changes slightly between measurements
How are instrumentation bias controlled?
Standardize measurement conditions as much as possible across all comparison groups
Regression to the mean
Initial score on the DV is extreme low or high
How are regression to the mean bias controlled?
Control group with the same starting average
