Which of the following is an attempt to make groups equal and diminish threats to internal validity?
A) Randomized assignment of participants to groups or conditions
B) Randomized assignment of treatments or conditions to intact groups
C) Checking for pretest equality of groups after the fact
D) All of the above are true

Question

Quizplus · Accepted Answer

All of the options listed are strategies aimed at enhancing the internal validity of an experiment by attempting to ensure that groups are equivalent at the outset of the study. Random assignment of participants or treatments helps to control for confounding variables by distributing potential sources of variation across the groups randomly, thereby making the groups more comparable.

Which of the Following Is an Attempt to Make Groups