Today anyone can write a review online. Yelp, Amazon etc. all give you the option, and most encourage you to write a review. But how do you know who’s review is any good?
Ask reviewers to also give their “credentials”. These can be anything that is relevant to the subject matter they are reviewing. Education, experience, publications etc. all with some references. Possibly have these reviewed by editors to try and confirm them. The reviewer gets a platform to boost their authority, and the reader gets credible reviews.