Grace randomly assigns college-bound African-American students to an intervention to improve mathematics achievement or to a control condition. A participants in a control group told Grace, the researcher, that his group found out that 'the other kids were getting a program to help their math scores' and therefore they decided to get together in a study group once a week to help each other. Grace was very concerned. What threat does this student action represent?
A) John Henry effect
B) Multiple treatment interference
C) Experimenter effects
D) Treatment diffusion

Question

Quizplus · Accepted Answer

The John Henry effect occurs when control group participants alter their behavior due to knowledge of the experimental group receiving a treatment, often trying to outperform the experimental group.

Grace Randomly Assigns College-Bound African-American Students to an Intervention to Improve