Question

differences between extraneous,intervening and moderating variable

Answer 1

Intervening variable A variable that explains a relation or provides a causal link between other variables.

Also called by some authors “mediating variable” or “intermediary variable.”

Example: The statistical association between income and longevity needs

to be explained because just having money does not make one live longer. Other

variables intervene between money and long life. People with high incomes tend

to have better medical care than those with low incomes. Medical care is an

intervening variable. It mediates the relation between income and longevity.

Exogenous variable A variable entering from and determined from outside of the system being studied.

A causal system says nothing about its exogenous variables.

Moderating variable A variable that influences, or moderates, the relation between two other variables

and thus produces an interaction effect.