The problem is that the linear 5-star rating makes it difficult to truly impart an opinion on the minor imperfections of a book. Does a minor defect warrant a 20% cull (1-star) on the review? It depends a lot on your own personality, if you're the type that tends to be forgiving and lenient then you'll err to the 5-star, if otoh you're stern and absolute you'll fall to the 4-star position.
Personally I liked the multiple field 5-star rating, where you can rank the various attributes of the book (spelling/grammar/proofing, typesetting/layout, plot, characters), of course that'll tend to put off a lot of potential reviewers.
|