Question

A repeated-measures research design tends to have which of the following drawbacks?

		the possibility for extraneous variables that occur over the passage of time to influence results
		the need for a larger sample size
		less of an ability to control the extent to which individual differences among research participants influence results
		the need to provide more evidence to support statistical significance than other research designs

Answer 1

Repeated measures design is a design model in which each member of the group in an experiment or a study is provided with different treatments or conditions over time.

It's major drawback from the mentioned options is "less of an ability to control the extent to which individual diferences among research participants influence results" which is the correct answer.

In the repeated measures design, the researcher has no control over the indiviual differences that occur as the same participant goes through all the conditions whic can result in carry-over effects or fatigue. This in the end influences the result.