Final answer:
An Instance Qualifier is used to provide a unique identifier to each instance of the competency so that you can determine who provided what rating.
Step-by-step explanation:
When multiple people update a performance rating for a competency on a worker's profile, an Instance Qualifier is used to provide a unique identifier to each instance of the competency so that you can determine who provided what rating. An instance qualifier allows you to differentiate between different versions or instances of the competency.
For example, if two people update the performance rating for a competency named 'Communication Skills' on a worker's profile, the instance qualifier could be the date of the rating or the name of the person who provided the rating, ensuring that each rating is uniquely identified.