This article helps you with how a user can rate the meetings that they have attended throughout the event.

Once the user login to his/her profile, there is an option in the left menu section called "Meeting Ratings":

On clicking on"Meeting ratings" a user can see all the meetings along with the information related to it such as Subject, Meeting With, Date/Time:

In the column "Rating" a user can give a rating which serves as a feedback for that meeting.