This criterion is concerned with the author's expertise or authority on a subject. Choose books written by those who are knowledgeable in the subject you are researching. You can also check directories for an author's educational background and work experience. Check to see if others who are writing on the subject cite the author favorably or negatively or look for citations to the author's work in bibliographies on the topic. The reputation of the publisher or sponsoring agency can also indicate quality.
Books published by university presses or major publishers in a discipline are more reliable.
The title of the source can be a good indicator. When a book has a long title, the complete title may not appear on the spine or cover of the book. Look on the title page for the complete title. If you locate the citation to a book in a source that contains abstracts or summaries, be sure to read the abstract. Subject headings or descriptors from electronic databases and print abstracts or indexes also offer excellent clues about a book's content.