Match the Research Examples in 1-7 with the Main Threat

Multiple Choice

Match the research examples in 1-7 with the main threat to internal validity that it contains (a-g) .
-The research assistants become bored and do not do their observations as carefully near the end of the study.

A) Maturation
B) History or environmental events
C) Repeated testing
D) Instrumentation
E) Selection or assignment
F) Mortality or attrition
G) Statistical regression