What is an observational​ study?

A.
An observational study measures the value of the response variable without attempting to influence the value of either the response or explanatory variables.
B.
An observational study is a list of all individuals in a population along with certain characteristics of each individual.
C.
An observational study is when a researcher assigns individuals to a certain​ group, intentionally changing the value of an explanatory​ variable, and then recording the value of the response variable for each group.

1 answer

A. An observational study measures the value of the response variable without attempting to influence the value of either the response or explanatory variables.