  Measurement uncertainty is a non trivial aspect of the laboratory component
of most undergraduate physics courses. Confusion about the application of
statistical tools calls for the elaboration of guidelines and the elimination
of inconsistencies were possible. Linear regression is one of the fundamental
statistical tool often used in a first year physics laboratory setting. In what
follows we present an argument that leads to an unambiguous choice of (a)
variable(s) to be used as predictor(s) and variable to be predicted.
