Answer:
a) reduce bias in
Explanation:
By keeping the performance diary for each of her employees the shift supervisor is actually keeping the record of the performance of the employees.
Maintaining this record will help in giving performance appraisals i.e the appraisal based on the actual performance of the employees over the period of time rather than providing appraisal on the basis of how well the supervisor is in contact with the particular employee i,e it will reduce the bias in appraisal.
