A researcher is evaluating the changes in performance that occur during a six-week training program. Participants are observed at the beginning and at the end of the program and the researcher rates each individual's level of performance. When the researcher's standards for rating performance change from the first observation to the last, then the internal validity of the study is threatened by ____.
A) history
B) instrumentation
C) maturation
D) statistical regression

Question

Quizplus · Accepted Answer

Instrumentation refers to changes in the measurement tools or standards used to assess performance. If the researcher changes their standards for rating performance between the first and last observation, it could introduce a systematic bias in the results, leading to a threat to internal validity. History refers to external events that might affect participants' performance, maturation refers to changes that occur naturally over time, and statistical regression refers to the tendency for extreme scores at the first observation to regress towards the mean at the second observation, which is not relevant in this scenario.

A Researcher Is Evaluating the Changes in Performance That Occur