What are the ten threats to internal validity?

Question

What will be an ideal response?

Answer 1

Students should identify and explain:
A) Selection Bias - a threat to internal validity when groups in an experiment are not equivalent at the beginning of the experiment with regard to the dependent variable.
B) History Effects - a threat to internal validity due to something that occurs and affects the dependent variable during an experiment, but that is unplanned and outside the control of the experimenter.
C) Maturation Effects - a threat to internal validity in experiments due to natural processes of growth, boredom, and so that occur during the experiment and affect the dependent variable.
D) Testing Effect - a threat to internal validity that occurs when the very process of measuring in the pretest can have an impact on the dependent variable.
E) Instrumentation - a threat to internal validity that occurs when the instrument or dependent variable measures changes during the experiment. This threat is related to stability reliability.
F) Experimental Morality - threats to internal validity due to subjects failing to participate through the entire experiment, especially if it is many participants or more from one group than another.
G) Statistical Regression - a threat to internal validity that is a problem of extreme values or a tendency of random errors to move group results toward the average.
H) Diffusion of Treatment - a threat to internal validity that occurs when the treatment "spills over" from the experimental group and control group subjects modify their behavior because they learn of the treatment.
I) Compensatory Behavior - a threat to internal validity that occurs when subjects in the control group modify their behavior to make up for not getting the treatment.
J) Experimenter Expectancy - a type of reactivity and threat to internal validity due to the experimenter indirectly making subjects aware of the hypothesis of desired results.