Grace conducts research on race and achievement in mathematics. She designs a study to see if a new intervention she designed increases African-American students' math achievement scores. She goes to a local school with a representative Aftrican-American student population and randomly assigns college-bound African-American students to the intervention or to a control condition. Grace gives a mathematics achievement test in September to both groups. Through the academic year the treatment condition receives the intervention. She uses end of year achievement tests to see if there are differences between conditions.
-Grace found that students studied together for the end of year achievement tests. She believes that some of the students in the treatment condition shared intervention information with the control group. Which of the following threats does Grace now have to be most concerned about?
A) Maturation by treatment
B) Treatment diffusion
C) Selection by treatment
D) Statistical regression

Question

Quizplus · Accepted Answer

Treatment diffusion occurs when information about the treatment spreads to the control group, making it difficult to determine if any differences in outcomes are due to the treatment or to information sharing. Therefore, Grace should be most concerned about treatment diffusion in this scenario. Maturation by treatment refers to changes that occur over time that affect both groups equally, selection by treatment occurs when the groups are not equivalent at the beginning of the study, and statistical regression refers to the regression of extreme scores towards the mean. These threats are not as relevant to the current scenario.

Grace Conducts Research on Race and Achievement in Mathematics