Firsthand, original analysis (e.g. observations, interviews, surveys); Researcher collects or observes original data.
Secondhand analysis (e.g. articles, books, web sites); library catalogs, articles indices, web engines used to find.
Third person (e.g. dictionaries, encyclopedias, handbooks); library catalogs, articles indices, web engines used to find.
- authority (authors' education, experience, intentions)
- methodology (research, analysis)
- timeliness (appropriate publication date for topic)
- relevance (to topic)