Focused Searches
All Searches

Targeted Searching using Term Variants (Operators) – All Databases

How to use the operators OR, AND, NOT, ADJ, ADJn and FREQ to include term variants and build search queries systematically.

Databases – All

Ovid Training Team

2024-10-27

166 visits

Background

Overview

The Ovid platform provides a comprehensive selection of features and functions to help build robust search strategies that are able to cope with the complexities of both language and document composition. First and foremost among these features and functions are the so-called ‘operators’. Essentially, these are commands that instruct the search engine to combine search terms in a certain way. These commands, used individually but more usually in their combination, will enable you to carry out targeted searching. The operators available on Ovid are OR, AND, NOT, ADJ, ADJn and FREQ. An overview is given in the graphic below. Fuller details are provided in the Ovid Online Help as well as the Database Field Guide for the individual database you are searching in.

A note on the NOT Operator (See line #7):
When constructing searches using thesaurus terms in combination with free text terms, caution is advised with the NOT operator, as using it may run the risk of unwittingly excluding relevant documents. However, this operator is very effective for isolating document sets. 

A note on the ADJ and ADJn Operators (See line #4):
There are two variations of the Ovid proximity operator, ADJ and ADJn. The first, ADJ, carries out a regular phrase search finding the terms together in the order in which they have been entered. By contrast, the second variant, ADJn where ‘n’ is a number, carries out a search for the adjacent terms separated by n-1 words apart, the terms occurring in any order.

A note on the FREQ Operator (See line #12):
When used in Ovid, the FREQ or frequency operator shown in [Example 3], takes the form ‘x.ab./FREQ=n’ where ‘x’ represents a search term, ‘.ab’ the field in which the search should be conducted, here the Abstract  (AB) field, ‘freq’, the Ovid command for this function and ‘n’ the number of occurrences of term x being sought after. This operator can be used to great effect in full-text databases, such as the Cochrane Database of Systematic Reviews or YourJournals@Ovid. It can also be used meaningfully in text-rich fields such as Abstract (AB). In this Focused Search example, the terms being search for, i.e. truncated forms of the terms ‘migraine’ and ‘acupuncture therapy’ will return documents where these two ideas, occur together, at least 3 times each in the abstract field. The implication being that the returned documents are on point, are useful in their own right but can also be examined further to see how their subject headings and keywords treat the subject matter.

The 12 search expressions listed in this Focused Search also run on other bibliographic databases, for example, Embase on Ovid. Use the Change option on the Ovid platform to bring up the All Resources menu and select the database or the databases in combination, across which you want to search. 

Lastly, note too, the user created annotations, e.g. [Example 1]. These can be added to search lines when placed between block brackets [ ]. The annotations can also be added to, amended, or deleted using the Edit option available via the search screen under Actions / More / Edit.

Practice Suggestions

  1. Using the ADJ operator renders line #4 more succinct. How would further increasing the number ‘n’ impact your results? How can you test that the ADJn-based search expression is indeed delivering the search term words in the phrase combinations you expect?
  2. In [Example 2], in specifically search line #10, the US spelling of ‘randomized’ as well as the British spelling, ‘randomised’ are used. How could you use the ADJ operator to reduce the number of terms in the search expression, yet yield the same number of results for the search?
  3. The search in line #12 yields only three results. Name three ways with which you could derive additional benefits from using this search expression. 

 

Search Stategy

(adolescents or young adults or teenagers).ti,ab. [Example 1]

(adhd or Attention Deficit Hyperactivity Disorder).ti,ab.

(ritalin or concerta or daytrana or equasym or methylphenidate).ti,ab.

(adverse events or ((adverse or untoward or side) adj3 effects)).ti,ab.

1 and 2 and 3 and 4

(infant or infants or child or children or preschool or pre school).ti,ab.

5 not 6

(migraine or migraines or sick headache or sick headaches or status migrainosus).ti,ab,kf. [Example 2]

(acupuncture therapy or acupuncture treatment or acupuncture analgesia or ear acupuncture or electroacupuncture or meridians or acupuncture points or moxibustion).ti,ab,kf.

(randomized controlled trial or randomized controlled trials or randomised controlled trial or randomised controlled trials).ti,ab,kf.

8 and 9 and 10

migraine$.ab. /freq=3 and acupuncture therap$.ab. /freq=3 [Example 3]      

 

Launch Search

Reviewers

Primary: Michael Fanning

Secondary: Charlotte Viken

Review Date: 2024-10-27

Expiry Date: 2025-10-27

Original search produced by:

Ovid Training Team

Citation:

OvidGO! Portal. Focused Searches: Targeted Searching using Term Variants (Operators) – All Databases [Internet]. London (UK): Ovid Training Team (Editors); 2024 [updated 25 October 2024; cited 30 October 2024]. Available from: https://tools.ovid.com/ovidgo/searches/view.php?id=53