Knowledge Discovery using Fields (Title and Abstract) – All Databases

Background

Ovid MEDLINE, Embase on Ovid and more specialist resources like APA PsycInfo, are often described collectively as bibliographic databases. Or, even more specifically, as abstracting and indexing (A&I) databases. This description refers to a common feature they all share, namely that the record in the database is not the full-text equivalent of the original publication but a reflection of it. A reflection composed of specific units of information, called database fields whose own content or values have been gleaned from the original document and mapped to the database record. This process of converting the information from an original publication into a database record is carried out by indexers. The highly trained and qualified indexers at the National Library of Medicine (NLM) carry out this task for PubMed.

Generally speaking, original documents up for inclusion in the database, can be represented by their original title. The majority of these original documents, particularly those from scientific journals, will also have an abstract associated with them. These two pieces of information, taken over by the indexers ‘as is’, constitute the informational foundation of any database record. As such, rendered as the database fields, Title (TI) and Abstract (AB), either alone or in combination, they provide a sure and reliable way of retrieving information from any bibliographic database. Some of which, e.g.  Ovid MEDLINE and Embase on Ovid, are composed of tens of millions of records.

The recommended search mode for a Title (TI) and/or Abstract (AB) based search, either alone or in combination, is Ovid’s Advanced Search. Whereas in the previous Focused Search, the search terms adolescents adhd ritalin adverse effects were entered into the Basic Search search mode altogether in one line, the Advanced search can take and search for each term individually (see the search example, [Version 1: Terms as given], lines #1 to #4). The individual search lines can then be combined to achieve a result set that contains all of them (#5).

In this Focused Search the first iteration i.e. [Version 1: Terms as given] operates on the terms exactly as stated. So, for instance, the search engine only finds the term adolescent in its plural form. The singular version is not captured. Similarly the medication ritalin is only captured via its representation in the form of its brand name. The generic name of the medication, namely ‘methylphenidate’ is not captured. In such cases the term expressions can be enhanced using truncation and the addition of synonyms using the OR operator. See the search example, [Version 2: Terms enhanced], lines #6 to #10. For truncation Ovid employs the characters ‘*’ or ‘$’. Also known as ‘wildcards’, these can be used to search for ending variations of a word. See the Focused Search Targeted Searching using Term Variants (Wildcards) – All Databases for more detailed coverage of wildcards.

Practice Suggestions

1. Line #3 of the Focused Search retrieves a number of results for ritalin.ti,ab. As an alternative, run a truncated version of the search expression, i.e.  ritalin*.ti,ab. Drug trade names do not usually have a plural form, so what were you expecting? What did you find?
2. In Ovid it is possible to set the number of letters (n) that should follow the truncated search term prefix. Run the search expression  ritalin*1.ti,ab. To find ‘ritalin’ plus ‘ritalin plus 1’ additional character. Are the additional results relevant? 
3. Although the NOT operator can only be used via the command line, it is a very useful means of separating out sets of results. Use the NOT operator to isolate the additional results obtained from the previous search. What do the isolated results have in common?

  

Search Stategy

Copy Strategy 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

References:

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

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OvidGO! / Skills Videos
What are Boolean Operators?
What are wildcards?
How to change databases on Ovid?

Citation:

OvidGO! Portal. Focused Searches: Knowledge Discovery using Fields (Title and Abstract) – 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=52