Targeted Searching using Term Variants (Operators) – All Databases

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. Drawing upon six examples of common questions that are often put to Ovid Customer Support, this Focused Search looks at how operators, wildcards and commands can be used to effect across databases on the Ovid platform. Fuller details are provided in the Ovid Online Help as well as the Database Field Guide for the individual database you are searching in.

Example 1:
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.

Example 2:
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 as the example demonstrates.

Example 3:
Spelling variations are a challenge when formulating search expressions. Not only are there regional spelling differences, e.g. British versus American spelling, but also very commonly, singular and plural forms of words. Ovid provides a comprehensive selection of so-called ‘wildcards’ to accommodate these differences. Generally speaking, wildcards are symbols that can be used as character replacement holders. Some wildcard characters can be entered with numbers to indicate the number of characters for which a place or places should be held.

Example 4:
When used in Ovid, the FREQ or frequency operator, 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. PHQ-9, PHQ-15 and GAD-7 refer to established forms of reporting patient outcomes (PROs). Used at times individually, they are also deployed in combination. The searches as depicted in Example 4 yield records indicating that the mixed use of PROs is a dominant theme in the retrieved records as opposed to being simply mentioned.

Example 5:
Results from a search in a single database can be deduplicated. The Ovid command for this is ..dedup n where ‘n’ is the number of the search line whose records are to be deduplicated, e.g. line 8. In the search history, however, the completed function is displayed as remove duplicates from 8. Ovid can also deduplicate records obtained from searches across multiple databases.

Example 6:
Although Ovid performs phrase searching by default, quotation marks “ ” , can be used to require Ovid to search for the expression as a literal string. This is particularly helpful when the string includes special characters, such as a forward slash (/) or reserved words, such as the word ‘use’. On the Ovid platform the word use is interpreted as a command. In combination with a database’s abbreviation, e.g. medall for Ovid MEDLINE ALL, Ovid understands this expression as a command, i.e. use medall to change from the resource you are in, to the database, Ovid MEDLINE ALL.

The 12 search expressions listed in this Focused Search also run on other bibliographic databases, for example Embase on Ovid and APA PsycInfo. 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. [Ovid Trainer: Example 6]. 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.

 

Search Stategy

Copy Strategy Launch Search

Reviewers

Primary: Michael Fanning

Secondary: Charlotte Viken

Review Date: 2024-07-15

Expiry Date: 2025-07-15

Original search produced by:

Ovid Training Team

References:

Ovid / Database Field Guides
Ovid MEDLINE / Advanced Searching
Embase on Ovid / Advanced Searching

---

OvidGO! / Skills Videos
What are Boolean Operators?
What is an adjacency operator?
What are wildcards?
How to discover how many records are in an Ovid database?
How to change databases on Ovid?

Citation:

Ovid Customer Support, Utilising Term Variants (Operators, Wildcards & Commands) – All Databases, OvidGO! / Focused Searches, Version: 8th May 2024. Visited: < Insert Date >.