I work with education data and get scores back for all students in a school. Then I get the question, is their score statstical significantly different from students at another school, or different withing the group among race or gender.
Correct me if im wrong but t-tests are intended to tell whether samples can indicate whether the population means are different.
However, in this case, dont i already have the populations? I have all the objects of measurement im interested in. Or is there an abstract definition of the populations tacitly?
So i can already answer the question about whether the means are different…? Is the question actually about measurement error, and not sampling error? If so, is a t-test able to address measurement error?