A researcher trains observers to complete checklists while observing children's behavior on the schoolyard during recess.Over the course of the study,observers become more reliable in their observations.Any effect of a treatment in this study might be confounded with an ____________ threat to internal validity.
A) observation
B) instrumentation
C) additive
D) expectancy effect

Question

Quizplus · Accepted Answer

The improvement in reliability of observations over time might be due to changes in the observers' ability to use the checklists (i.e., instrumentation), rather than the actual treatment being studied. This is a potential source of confounding and a threat to internal validity.

A Researcher Trains Observers to Complete Checklists While Observing Children's