Final answer:
d. Performance rating methods
Performance rating methods are used to assess employee productivity through multi-source feedback, including the 360-degree feedback appraisal, to provide a well-rounded view of performance and areas for improvement.
Step-by-step explanation:
The methods used to compare employee performance to a set of standards to identify a number or letter that represents the employee's productivity levels are known as performance rating methods. Performance appraisals, such as the 360-degree feedback appraisal, involve assessments from various sources including supervisors, peers, subordinates, and sometimes customers, to gain comprehensive insights into the employee's work and to provide opportunities for improvement. However, such ratings can be subjective and variable, leading to discussions that could help the employee understand different perspectives and areas for personal development.