Bess Has Conducted a Pretest-Posttest Control-Group Study to Raise Math

Multiple Choice

Bess has conducted a pretest-posttest control-group study to raise math scores among fifth-grade students who have failed math. She has controlled the potential problem of __________ because she has selected participants for the experimental and control groups from the same pool of extremely low-scoring participants.

A) diffusion of treatment
B) instrumentation
C) selection
D) statistical regression