The Flaggedrevs Extension
Wikibooks has a special software feature called Flagged revisions, or flaggedrevs for short. Flaggedrevs allows users to review pages and grade them based on their quality. Readers and editors make some of the best reviewers because they see a large number of pages here on Wikibooks, while authors may tend to only see the books they are writing.
Flaggedrevs allows users with special permissions called "Editor" and "Reviewer" to review and grade pages. Editor permissions are automatically given to Wikibooks users after a certain amount of time, and after a certain amount of edits have been made. To get editor permissions earlier, or to get them if you aren't an active contributor, write a request at WB:RFP.
There are three judging criteria in flaggedrevs: Composition, Accuracy, and Coverage. Composition is the quality of the writing, Accuracy is the verifiable truth value of a page, and Coverage is the breadth and depth of the material. In each criterion there are 5 levels of quality: Poor, acceptable, good, great, featured. "Featured" is typically reserved for pages that are so good that other pages should use them as an example. Users with editor permissions can mark a page poor, acceptable, or good. Reviewers can mark a page as being great or featured. Because of this difference, Reviewers need to have a discerning eye for quality writing, and should probably be familiar with some of the content discussions at Wikibooks. See WB:FB and WB:RFD for examples of places where we discuss the quality of books.
Reviewing a Page
Reviewing a page is easy, once you have the permissions. At the bottom of a reviewable page is a box with several controls and a button in it. To review the page, set the appropriate level options in the box, and then click to save it. In some situations, you may be asked to enter a comment describing why you marked a page in the way that you did.
Note that you cannot mix a "poor" review level with the "acceptable" level. For a page to be considered stable, it must at least have an acceptable level of composition, accuracy, and coverage. Pages that do not meet this level of criteria should be treated as drafts, where users that do not yet have editor privileges will expect their changes to be applied immediately.
When reviewing a page, there are four levels describing the quality of the page. Knowing how to review a page means knowing how to judge a book using the criteria for each of the levels. The levels are more than just grades for the page, they are also a checklist that editors can follow to bring a page up to the quality seen in a featured book. If all the pages in a book are basically featured quality, the book could easily be nominated for the honor at WB:FB. Of course, having individual pages be featured book quality doesn't mean that the book itself is also featured quality. There needs to be an emergent quality to the book where pages build on each other in a logical and consistent way for the book to become featured. If the pages don't work together, the book is probably more of a macropedia than a textbook and needs additional work.
When reviewing the basic quality of a page ask yourself, "How well is it written?" Wikibooks is a text-based content website, so everything we do here revolves around the quality of our writing. The Wiki process does not demand that everything be written perfectly, but that successive editors and authors can improve a page incrementally by fixing errors and omissions as they are found. Pages should aspire to be technically correct in terms of spelling and grammar, but must also have flow, consistency, and structure. Readers hate to be presented with a bland wall of text, so things like headings, lists, templates, tables, and images should be employed to break the page up into bits that a reader can easily absorb.
Well-presented information is also only as good as its accuracy. If a page is well-written and has good coverage, it's still worthless if it's untrue or misleading. Wikibooks is an educational resource, and should aspire to teach accurate information to readers.
Even then, if the amount of material that a page actually covers, as compared to the amount of material that it should cover, is lacking, its quality may suffer. Good coverage means that a page covers all the topics that it intends to cover, and covers all of them well. Consider a page called "Arithmetic" that only covers addition, or a page called "Animals" that only covers mammals. Or, consider a stub page which only has a few short sentences about a large number of topics, without actually providing any interesting information about any of them.
The composition, accuracy, and coverage of content all need to be taken into account when reviewing. There are four levels that reviewers can make use of to indicate where a page stands.
This page either hasn't ever been reviewed, or else it has been reviewed and is terrible. Spelling and grammar is off, the page has no flow and makes no sense. Accuracy of content may be poor, with the page nothing short of absurd, talking about pseudoscience, nonsense, or other garbage. The content is untrue, misleading, and may even be dangerous to readers. These pages are also typically incomplete stubs, that provide only a brief overview, or only contain a lot of empty sections.
This page uses proper spelling and grammar and is written so that other people can read and understand it. Spelling and grammar don't need to be perfect, but it should be reasonable and easy enough for an experienced editor to clean up quickly. Accuracy of the content may be lacking with important details missing and certain aspects incorrect. The page will be short on examples, and short on discussion to explain things in an understandable way. It includes the bare amount of information on the topic, and doesn't include background information, references to other topics, examples, or in-depth discussions. This page needs an author to sit down and start drafting more content as soon as possible.
Once the words are spelled correctly and the sentences are constructed properly, it's time to focus on the overall structure of the page. Ideas should flow logically from one paragraph to the next. Later topics should build on earlier topics without going on tangents or requiring prerequisite knowledge that has never been discussed. The page should be broken down into sections and subsections, and maybe use some templates and tables to include additional information. The information it presents is not obviously incorrect, and maybe only suffers in certain details and lacks references. The page should probably include a high-level overview, some examples, some background information, and other pieces of information that readers will want.
Consistent style is the next step in page development. The page should not just be technically correct in spelling and grammar, or written with good paragraph and section structure. The page must be written in a consistent voice that properly accounts for the target audience. Wikijunior books for children should be written with high-energy and child-friendly vocabulary. Books for students, adults or professionals should all be written accordingly. To achieve this, the authors of a page should probably be familiar with pages like Wikibooks:Reading Levels. The page presents correct information, but also provides the tools to prove that the information is true. This proof can come in many ways including references to primary sources, do-it-yourself verification, or building logically on topics covered in other pages from the same book. Some books may require a certain amount of prerequisite knowledge in readers, and will take certain facts to be self-evident, so this should be considered when reviewing. Readers should be able to read this page and get all the information that they need on the topic. The page should have lots of good examples, in-depth discussions, overviews, and background. The page should set the reader up with all the information they need on this topic throughout the rest of the book, and maybe more than that.