The strongest possible manipulation should not be used if it results in c. ceiling effects.
When does a ceiling effect happen?
A ceiling effect happens when the manipulation pushes all or most of the participants to the maximum possible score on the dependent variable.
This can make it difficult to detect any differences between the groups, as everyone is already performing at their best. It makes results very difficult to interprete.
Floor effects occur when the manipulation pushes all or most of the participants to the minimum possible score on the dependent variable. This is the opposite of ceiling efffect.
Full question
The strongest possible manipulation should not be used if it results in Select one: a. statistically nonsignificant data. b. floor effects. c. ceiling effects.