Although confounds usually threaten internal validity, they A  design confound can counteract the true effect of an IV. can apply to null effects. Design Confounds Acting in Reverse - Definition: a design confound that is actually counteracting some true effect of the IV on the DV I saw the below example, but still don't understand. Example: In a GRE test prep study (comparing test prep group to no-test prep group) …perhaps the test-prep group was also under additional pressure to perform well on the GRE. As a result, they were actually receiving test prep and pressure, whereas the no-test prep group didn’t have test prep or pressure. This confound would work against the test-prep group, lowering their scores.   What do reverse design confounds mean? Please explain with an example. (Please type, no handwriting)

Although confounds usually threaten internal validity, they
A  design confound can counteract the true effect of an IV.
can apply to null effects.

Design Confounds Acting in Reverse
- Definition: a design confound that is actually counteracting some true effect of the IV on the DV

I saw the below example, but still don't understand.

Example: In a GRE test prep study (comparing test prep
group to no-test prep group)
…perhaps the test-prep group was also under additional pressure to perform well on the GRE. As a result, they were actually receiving test prep and pressure, whereas the no-test prep group didn’t have test prep or pressure. This confound would work against the test-prep group, lowering their scores.

What do reverse design confounds mean? Please explain with an example. (Please type, no handwriting)