Which of these is essential to every correlational study?

Question

Quizplus · Accepted Answer

A correlational study requires a group of subjects to study in order to examine the relationship between two variables. The ability to focus on just one variable may be helpful, but it is not essential to every correlational study. Likewise, the chance to collect responses with maximal impact on the variable of interest may be desirable, but it is also not essential. Finally, a single subject who will agree to in-depth testing would be appropriate for a case study, but not necessarily for a correlational study.

Which of These Is Essential to Every Correlational Study