What is another term for the variables analyzed in correlation research?

In correlation research, the primary focus is on examining the relationship between two or more variables without manipulating them. The variables being analyzed in this context are referred to as co-variables. This term highlights that the study is investigating the way in which these variables change in relation to one another. Unlike independent and dependent variables, which are used in experimental designs to denote cause and effect, co-variables simply exist and are measured to identify any potential associations. This distinction is crucial because correlation studies do not imply causation; they only explore the strength and direction of relationships between different factors. Control variables, on the other hand, are factors that researchers account for to minimize their effect on the outcome but are not the primary focus of correlation studies. Thus, co-variables is the most appropriate term in this context.