A researcher evaluates the effectiveness of an art class by having an art expert judge the quality of student's paintings at the beginning of the class,in the middle of the class,and at the end of the class.If the art expert's standards for judgment change during the class,then the internal validity of the study is threatened by
A)history.
B)instrumentation.
C)maturation.
D)regression toward the mean.

Question

Quizplus · Accepted Answer

Instrumentation refers to changes in the measurement tool or the way in which the measurement is taken, and in this case, the art expert's standards for judgment may have changed over time. If this occurs, it could impact the internal validity of the study because it introduces a potential confounding variable.

A Researcher Evaluates the Effectiveness of an Art Class by Having