Goodreads: Ratings and Reviews
Can apply to: Any book that has been added to the Goodreads catalog
Metric definition: Goodreads users rate books on a scale from 1-5 stars and offer their personal review and commentary.
Metric calculation: A book’s overall rating is the average of all ratings provided by Goodreads users.
Data sources: Goodreads book pages
Appropriate use cases: Reviews may provide qualitative evidence of impact upon the reviewer(s). Ratings and reviews may be useful as evidence of perceived quality by scholars and the general public.
Limitations: Goodreads has more than 55 million users who have written 50 million reviews on 1.5 billion books. Inclusion in Goodreads ratings and reviews is driven entirely by the users rather than the quality or significance of particular books. Most Goodreads users who provided an address are located in the United States, although there are many users across the globe. Only one in five books in PlumX have Goodreads reviews.
Inappropriate use cases: User ratings and reviews should not be used as measures of scholarly impact, as only a very weak correlation between the two metrics has been found to date (for history monographs).
Transparency: Ratings and book reviews are publicly accessible.
Timeframe: Ratings and reviews are publicly accessible as soon as the user posts them.