A reference source is usually compiled by many people. Look for procedures that encourage contributors to produce quality work:

• Are contributors required to use their real names?
• Can contributors earn additional responsibilities based on their work?
• Are contributions fact checked and polished by an editor?

If contributors are identified, their expertise and credentials should relate to your subject. A credible author or subject editor might:

• Have a degree in this subject
• Study or do research on this topic
• Work in a related field