That question can never be answered with absolute certainty or be proven, but strong support for the validity of a construct or variable can be developed. The support for four types of validity is necessary in research: content, criterion/predictive, construct, and convergent-discriminant validities. Concurrent validity, which is similar to criterion/predictive validity may also be necessary depending on the situation and type of research. Note, that it is possible that a construct or variable that is in fact valid will fail one or more of these tests or that a construct-variable that isn’t variable will pass one or more of these …show more content…
Changes ranging from fatigue, aging, developmental changes etc. Note, all of these changes happen within the participant. For example if I want to test employees performance on the job pre-test and post-test, the subjects would obviously learn thing on the job to do the job better therefore it would challenge the validity of the study.
• History: concerns the changes that take place due to the passage time between the pretest and posttest. Very similar to maturation except the changes are happening to the participants rather than within the participants. For example if a researcher was conducting a study about depression and one of the subjects mother dies this would challenge the validity of the study.
• Mortality: This threat takes in account the participants that drop out of the study between pre-test and post-test. When participants drop out in the middle of the study this causes the nature of the population sample to change which would empirically threaten the validity of the study. The sample might not be representative any longer because of the changes in the size of the sample.
• Instrumentation: This speaks to problems or issues that might occur with the instrument or the way the researcher is measuring the dependent variable. This could arise as a result a several reasons like using different instruments or calibration issues