_____ is a threat to internal validity due to changes in how a variable is measured during the course of an experiment.
A) A testing effect
B) A carryover effect
C) A practice effect
D) Instrumentation

Question

Quizplus · Accepted Answer

Instrumentation refers to changes in the calibration of a measurement tool or changes in observers that might lead to inconsistencies in the measurement across the study, thus threatening internal validity.

_____ Is a Threat to Internal Validity Due to Changes