This doc describes how to use simple keywords and elasticsearch boolean query syntax to retrieve records from DOAJ. Note that API-based searches NK executes utilize a different syntax than used via DOAJ website search.

Use AND /OR /AND NOT operators (case sensitive) to combine together keywords of interest, searched across all fields. In absence of operators, keywords will be ANDed together. For example, the search:

dizziness stroke

resolves to

dizziness AND stroke

which will retrieve results containing the words “dizziness” and “stroke” somewhere in the record. Use quotes to search phrases with spaces and parentheses for longer search strings.

dizziness AND NOT “heat exhaustion” AND stroke AND (elderly OR senior)

This query retrieves records containing “dizziness” and “stroke”, but not “heat exhaustion”; the record must also reference “elderly” or “senior” populations.

To generate more a more precise search on specific fields, use the following syntax: field:keyword. For example: title:stroke will retrieve only records containing stroke in the title. Commonly used fields include:

• title
• abstract
• publisher (journal name)
• bibjson.journal.language
• bibjson.author.name
• bibjson.year
  • Most commonly used in combination with range syntax, e.g. bibjson.year:[2015 TO 2022]

More details here. Field searches may be combined as keyword searches above:

title:stroke AND abstract:“IV-TPA” AND bibjson.journal.language:en

DOAJ API searches are limited to 1000 records; this means you may only retrieve 1000 records per search on Nested Knowledge. By default, Nested Knowledge will truncate your search to the top 1000 results by relevance.

If you require a comprehensive search that exceeds 1000 results, you must break your search into pieces using more refined criteria. An easy way to accomplish this is using publication year (field bibjson.year) limits. For example, the search:

(elderly OR senior OR caregivers) AND isolation

retrieves 1013 results at the time of writing. We can break this into two smaller searches, beneath the limit, around the year 2019:

(elderly OR senior OR caregivers) AND isolation AND bibjson.year:[1900 TO 2019]

(elderly OR senior OR caregivers) AND isolation AND bibjson.year:[2020 TO 2022]

See DOAJ search documentation for full search syntax, including a wider variety of elasticsearch operators available.

Unless you are using keyword-only searching, do not test your query against doaj.org's search interface. It uses an incompatible, more limited syntax (e.g. does not allow parentheses) that is less suited to systematic review.

Instead, test your search within your nest:

• Check the number of results you will retrieve using NK's search creation interface.
• If the number of results is within reason, run the search
• Filter to its results using the “Literature Search” filter in Study Inspector
• Skim results and use Inspector's Explore feature to make sure they match the intent of your search strategy
  • If you're unsatisfied with results, delete the search and refine.