THIS PAPER CONSIDERS THE EFFECT OF MEASUREMENT ERROR IN DETERMINING THE POSITIONAL REPEATABILITY OF AN INDUSTRIAL ROBOT. SIMULATION AND EXPERIMENTAL RESULTS DEMONSTRATE HOW THE CALCULATED VALUE OF REPEATABILITY VARIES AS A FUNCTION OF MEASUREMENT ERROR. IT HAS BEEN FOUND THAT LITTLE ATTENTION IS PAID TO SPECIFYING THE CHARACTERISTICS AND/OR TYPE OF MEASUREMENT SYSTEM THAT IS TO BE USED. IT IS SUGGESTED THAT THE CHOICE OF INSTRUMENTATION CAN HAVE A SIGNIFICANT IMPACT ON THE RESULTS OF REPEATABILITY TESTING AND SHOULD THEREFORE BE CONSIDERED IN SUFFICIENT DETAIL.