Christopher has developed a behavioral method that he believes will help people quit smoking.He recruits a group of 25 people who want to quit smoking and begins his intervention.By the time the intervention ends,only eight people remain,but they have all quit smoking.This is an example of a(n)____ threat.
A)history
B)mortality
C)instrumentation
D)regression

Question

Quizplus · Accepted Answer

Mortality threat (also called attrition threat) refers to the loss of participants from a study, which can lead to biased results if those who drop out are different from those who remain. In this case, the fact that only eight people remained from the original group of 25 could be seen as a mortality threat. However, since all of the remaining eight people were successful in quitting smoking, it is not a significant threat to the internal validity of Christopher's study. The other options are not applicable to this scenario: history threats refer to events that occur during a study that may affect its results, instrumentation threats refer to changes in measuring instruments during a study that may affect its results, and regression threats refer to the tendency for extreme values to become less extreme upon a second measurement (which does not apply here since Christopher did not take multiple measurements).

Christopher Has Developed a Behavioral Method That He Believes Will