Reliability in performance appraisal is measured by: a. correlating two sets of ratings made by a single rater or by two different raters. b. quantifiable performance standards. c. linking performance standards to organizational goals. d. correlating the ratings of an employee at two different points in time.

a. correlating two sets of ratings made by a single rater or by two different raters.

Explanation: Performance appraisal refers to a review of employee's job performance with regards to input, ethics and other key performance indicators employed by an organization. This is necessary in other to correct ineffective attitude of employees and improve output in other to meet organizational goals. Reliability of performance appraisal refers to the consistency and validity of the performance appraisal system which could be achieved by correlating the result of two sets of rating completed by a single rater or two different raters.

i would say b. research typically uses a variety of sources