hi morti,
if you talk about worker and formal appraisal then it is like asking the watchman during the selction process if he has presented any paper in conference...
formal appraisal is not needed first you can easily evauate the perforamcen of the worker from their productivity.then workers are not in postion to do slef apprasail or ticking the scales etc.,
so i think the need different type of appraisal which is effiective in their own domain