Learn Overton’s search syntax for phrases, proximity matching, searching specific fields and boolean queries
Simple keyword searches in Overton will return all of the documents containing those words, and you can then use the filters on the left hand side of the search pages to make your search more precise.
However, Overton also supports more complex queries using boolean operators (AND, OR and NOT), searches within specific fields and more.
Looking for phrases
By default, search strings are broken up into words and each one is searched for separately, so
income tax
will find all documents that contain both income and tax, even if they’re not next to each other (for example you’ll match the phrase “income from tax was high last year“).
To look for a phrase rather than individual words, put it in quotes. For example:
"income tax"
* Wildcard
Users can search for alternate ends of words using the ‘*’ wildcard. Wildcards are used in keyword searching to represent one or more characters. For example, a search for
Canad*
will retrieve documents that contain the words Canada, Canadian or Canadians.
One thing to note is that the ‘*’ wildcard can only be applied to single words and will not work for phrase searching using quotes.
Special characters
Overton is sensitive to diacritics. For example, querying Overton for “nino” will return different results than a search for “niño”.
If the name of a researcher you’d like to search for on the people tab contains accented characters, we recommend including its special characters :
eg: “Bernhard Schölkopf ” rather than “Bernhard Scholkopf“
Boolean operators
You can craft more complicated queries using AND, OR and NOT.
"covid-19" AND protection AND NOT masks
will return policy documents containing both “COVID-19” and “protection” but only if the document doesn’t contain “masks”
You can use brackets to signify which parts of the query should match first. For example:
(("data science" or "artificial intelligence") AND "governance") OR "AI ethics"
will match documents either containing “governance” as well as “data science” or “artificial intelligence”, OR the phrase “AI ethics”
Proximity searches
To search for words occurring near each other you can use the ~N operator, where N is how many words are allowed in between each part of your phrase.
For example:
"data science"~1
will find documents containing the words “data” and “science” next to each other or with one word between them where “data” appears first and “science” appears second (e.g. “data science” and “data and science” would match, but “data indicates that science” and “science of data” wouldn’t).
Searching specific fields
You can find policy documents with words within specific fields or in some cases, documents that have been assigned an specific identifier. A few things to note about searching within specific fields
- specific field searches must be at the start of your search query
- you can only search one specific field at a time
- all the words after the prepend will be included in your query
- you can combine specific field searches with other techniques like phrase searching, proximity searches and using Boolean operators.
The following prepends can be used to search within specific fields.
title:gender equality STEM
will return results with all the words anywhere within the title of a policy document
title:"tobacco packaging"
will return results with the exact phrase “tobacco packaging” within the title of a policy document
abstract:climate
will return documents that have the word “climate” in either their title or abstract. It is important to note that not all policy documents have available abstracts.
author:"Erica Smith" OR "E Smith"
will return articles authored by Erica Smith or E Smith (this prepend only works in the Search Scholarly Articles search).
domain:brookings.edu
will return documents that cite specific domains
If Overton collects a site-specific identifier like a catalog number or DOI (we only do this for certain sources), you can search using the id: prepend.
id:JRC127215 OR JRC127882
will return documents with a site specific ID matching JRC127882 or JRC127215 (in this example the identifiers are from the Joint Research Centre, an EU agency).