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Welcome aboard the research vessel of knowledge!
Navigating the vast ocean of literature can be daunting, but efficient search strategies are essential for academic and professional success. Let’s dive in and explore how thesaurus terms can help you sail smoothly through your literature searches, making your journey not only faster but also more fruitful.
Before we begin, it is often quite confusing as the term “thesaurus term” is also referred to as “controlled vocabulary” or “subject heading” or “indexed terms” depending on the database you are consulting. We will use these interchangeably in this article so you get used to seeing it but they perform the exact same function.
Think of thesaurus terms as concrete paths in your search journey.
Databases lay these paths for easier navigation: when authors use different subject terms for the same concept, thesaurus terms help to standardize these variations.
For example, all terms relating to cancer are grouped under the term “neoplasms” in PubMed. This means that article that uses the term cancer or tumor or tumour or neoplasm or malignancy will all be directed to the term “neoplasm”. These are particularly important when conducting a literature search for a literature review.
Indexed terms provide consistent labels for similar concepts, much like naming each star in the night sky for better navigation. This standardization helps researchers overcome variations in language and improves the precision of searches.
By using them, you can fine-tune your searches, ensuring you reel in the most relevant articles without being swamped by irrelevant ones.
Different fields have their own lingo, and thesauri are customized to reflect this.
For example, the Medical Subject Headings (MeSH) in PubMed provide detailed and relevant terms for healthcare topics, ensuring your search net is cast wide yet precise.
Using terms specific to your discipline ensures that you’re speaking the language of the field, much like a sailor using nautical terms for navigation.
Thesaurus terms save you time by eliminating the need to brainstorm all possible synonyms and alternative search terms. Instead, you can rely on predefined terms to capture relevant articles, making your search as efficient as a well-oiled engine.
Using predefined terms ensures that your search covers all bases, capturing comprehensive results without missing out on key information.
Thesauri are organized hierarchically, showing broader, narrower, and related terms. This hierarchy is like a treasure map, guiding you through the interconnected concepts.
For instance, in a medical database, “Heart Diseases” might be a broader term, with “Coronary Artery Disease” as a narrower term. Understanding these relationships helps you refine your search for more precise results.
The hierarchical structure allows for targeted searching, helping you find exactly what you’re looking for with your queries. For instance, if you’re researching the effects of a specific medication or disease, the thesaurus will direct you to not only the main term, but also its related concepts and variations.
For example, the thesaurus term (known as MeSH terms in PubMed) “Depressive Disorder” has the following terms related to it that are highly related to depression but may not use the term depression: e.g. Dysthymic Disorder, Premenstrual Dysphoric Disorder, and Seasonal Affective Disorder.
For a comprehensive, advanced search, combine controlled vocabulary terms with keyword searches. This dual approach ensures you capture both indexed articles and emerging concepts, like casting a net and a line simultaneously.
Use Boolean operators (AND, OR, NOT) to refine your searches. Think of them as the knots in your net, helping you control what gets caught.
Use truncation to broaden your search results, catching variations of a term. For example, searching for “educat*” will retrieve “education,” “educator,” and “educational.”
Each database may have its unique set of terms. For instance, what’s called a “subject heading” in one database might be a “descriptor” or “index term” in another. This can sometimes be very confusing.
MEDLINE/PubMed call theirs “MeSH terms” and can be queried in the MeSH database. Embase call theirs “emtree terms” while CINAHL and PsycINFO use “thesaurus of psychological index terms”.
Many databases allow you to “explode” a term, including all its narrower terms in your search. This method is like using a wide-angle lens, capturing the full picture.
Alternatively, you can “focus” on a term to retrieve only articles where it’s a major topic, akin to using a zoom lens for detailed exploration.
Check the subject headings of articles you’ve found useful. These headings can guide you like a lighthouse in a storm, pointing towards relevant thesaurus terms.
Utilize related terms and browsable thesauri in databases. They often suggest relevant terms, saving you from aimlessly drifting through endless possibilities.
Thesauri are regularly updated to reflect changes in disciplines. Like a ship’s logbook, they record new and emerging issues, ensuring your searches stay current.
For example, terms related to “Zika virus” or “SARS-CoV-2” have been added as these topics have gained importance.
Here’s a simple guide to using a thesaurus in databases:
For instance, in PubMed, you might use the MeSH term “Diabetes Mellitus” combined with keywords like “treatment” or “management.”
In summary, using thesaurus terms can significantly enhance your literature search efficiency by providing standardized, precise, and comprehensive search results.
Remember to combine thesaurus terms with keyword searches, use Boolean operators and truncation for better results, and leverage database-specific thesaurus features.
Consider joining our course “Complete Guide to Database Searching for Systematic Reviews“.
