I'm student of MBA and as per my knowledge BARS i.e. behaviourally anchored rating scale is one of the method of performance evaluation.
BARS specify definite, observable and measurable job behaviour. Examples of job related behaviour and performance dimensions are found by asking participants to give specific illustrations of effective and ineffective behaviour regarding each performance dimension.these behavioural examples r then translated into a set of performance dimension, each dimension having varying levels of performance.the results of this process r behavioural descriptions, such as anticipates, plans, executes, solves immediate problems, carries out orders, and handles emergency situations.