A researcher conducted an online study at the beginning of the semester. When the data were downloaded at the end of the term, she realized she had not included one of the experimental conditions, so she reopened the study and collected data from new participants. This procedure resulted in
A) a natural confound.
B) a treatment confound.
C) an artifact.
D) a measurement confound.

Question

Quizplus · Accepted Answer

By adding a new experimental condition after the study has already begun, the researcher has created a treatment confound. This is because the new condition is not equivalent to the original conditions, and therefore any observed effects cannot be attributed solely to the manipulation of the intended independent variable.

A Researcher Conducted an Online Study at the Beginning of the Semester