Threats to Internal Validity

Question 1

A study has ___________________ validity when it allows an investigator to determine if there is a causal relationship between independent and dependent variables.

Answer 1

Internal.

Question 2

Campbell and Stanley (1963) identified ___ “generic” extraneous variables that can threaten a study’s internal validity.

Answer 2

8.

Question 3

Threat to Internal Validity - ____________________: Refers to any biological or psychological change that occurs within subjects during the course of a study as a function of time, is not relevant to the research hypothesis, and affects the status of most or all subjects on the dependent variable in a systematic way.

Answer 3

Maturation.

Question 4

Threat to Internal Validity - ____________________: Occurs when an external event systematically affects the status of subjects on the DV. Can be controlled by including more than one group in the study and randomly assigning subjects to groups.

Answer 4

History.

Question 5

Threat to Internal Validity - ____________________: Threatens whenever exposure to a test alters subjects’ performance on retesting.

Answer 5

Testing.

Question 6

Threat to Internal Validity - ____________________: Occurs when changes in the accuracy or sensitivity of measuring devices or procedures during the course of a study can confound the study’s results.

Answer 6

Instrumentation.

Question 7

Threat to Internal Validity - ____________________: Occurs whenever subjects have been selected because of their extreme status on the DV or a measure that correlates with the DV, due to the tendency of extreme scores to move toward the mean when the measure is readministered to the same group of people.

Answer 7

Statistical Regression.

Question 8

Threat to Internal Validity - ____________________: Occurs whenever the method used to assign subjects to treatment groups results in sytematic differences between groups at the beginning of the study.

Answer 8

Selection.

Question 9

Threat to Internal Validity - ____________________: When subjects who drop out of one group differ in an important way from subjects who drop out of other groups.

Answer 9

Attrition (Mortality).

Question 10

Threat to Internal Validity - ____________________: When groups are initially nonequivalent, selection can act alone and/or interact with other factors to threaten a study’s internal validity.

Answer 10

Interactions with Selection.