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Study designs and validity threats

1. Explain and give examples of how the particular outcomes of a study can suggest if a particular threat is likely to have been present.

2. Describe each of the following types of designs, explain its logic,
a. Non-equivalent control group pretest only
b. Non-equivalent control group pretest/posttest
c. Cross-sectional

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1. Explain and give examples of how the particular outcomes of a study can suggest if a particular threat is likely to have been present.

When randomization is not used, such as with a quasi-experiment, the study is at a higher risk of confounds (threats). This is one of the main threats to the internal validity of a study. Quasi-experimental designs are considered to be weak designs, and thus the conclusions of these studies need to be interpreted carefully. Possible confounds may include a history effect, maturation effect, testing effect, diffusion of treatment, regression to the mean, ...

Solution Summary

This solution discusses threats to validity and different types of study designs

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