Wordpress, Rate Author/Users Feature

We have a website that is essentially a tool that lists conferences/organisers etc.

Each conference has an organiser (author) who has a profile page. The organisers can add conferences themselves.

We'd like to add a ratings system, whereby a user visits a page, they choose the conference they are rating and fills out a series of questions that are all star rated. These ratings should then feed through to the organisers page mentioned above to form an average star rating for each of the different questions asked, as well as comments that have been left.