What is intervening variable

An intervening variable (also known as a mediating variable) is a hypothetical variable used to explain causal links between other variables. It is not directly observable but is inferred from the relationship between the independent and dependent variables. For example, in the relationship between "studying" (independent variable) and "test scores" (dependent variable), "knowledge acquisition" could be an intervening variable, as studying leads to knowledge acquisition, which in turn leads to higher test scores.