Abstract: A series of theory and methods centering on the evaluation of form and position errors for cylindrical surfaces has been conducted. It deals with techniques to determine an optimum sampling interval, generalize mathematical model for form error evaluations, develop a kind of efficient algorathm. Of optimization, delete unneccesary measured data and verify measurement instruments and results. Such theory and methods have been proved correct and effective by experiments.

Key words: Assessment, Contour, Error, Measurement technique