Keyword searches return documents that include the word you searched for.
The search results could include:
- articles primarily about your topic
- articles sort of related to your topic
- articles that tangentially mention your topic, but which are about something else
Because keyword searches look for words, not ideas, you can miss important documents when authors use alternate spellings and synonyms. Unless you can think of all the possible alternate words that describe your topic, your search will be incomplete. In order to construct a thorough literature search with keywords, you would have to search with all of these different spellings and synonyms:
Example:
- Phthisis
- Pulmonary Consumptions
- Pulmonary Tuberculosis
- Pulmonary Tuberculoses
- etc.