How Do You Search for a Concept That Has No Agreed Name?

What if the concept exists but its name does not?

Some research concepts are recognizable long before researchers agree on what to call them. Different authors may use competing labels, describe the idea rather than name it, borrow terminology from neighboring fields, or use a broad term for something that another research community treats as a distinct construct.

This creates an unusual search problem. You are not simply looking for synonyms of a known term. You are trying to identify the vocabulary through which an unstable or loosely bounded concept appears in the literature. Searching only the label you happen to know can therefore produce a deceptively coherent but incomplete body of evidence.

The challenge is to search for the concept rather than become dependent on one name for it.

Search the concept through multiple plausible ways of expressing it

Searching becomes a problem of concept representation

Start by defining the idea before collecting words

When terminology is unstable, beginning with a list of keywords can put the cart before the horse. First write a short operational description of what you mean by the concept. What phenomenon must be present for a study to count as relevant? What would fall outside the concept even if an author used a similar label?

This conceptual boundary matters because terminology and meaning do not map perfectly onto each other. One concept can have several names, while one apparently useful term can refer to several different phenomena. A search strategy therefore needs both lexical coverage, meaning the words used to express the idea, and conceptual discipline, meaning a defensible account of what those words are supposed to represent.

This distinction becomes especially important when deciding whether two candidate terms are merely alternative expressions or actually represent different concepts.

Do not assume that every useful term will be a true synonym

If there is no established name, exact synonyms may be scarce. Relevant records may instead use near-synonyms, descriptive phrases, umbrella terms, narrower manifestations, older expressions, or terminology associated with a theoretical tradition.

Suppose you are interested in a newly recognized educational behavior. One research group may give it a concise construct label. Another may describe the same behavior in ordinary language without naming a construct at all. A third may discuss one particular manifestation of it. All three could be relevant even though their terminology would never appear together in a conventional thesaurus.

This is why the task is broader than simply finding different terms researchers use for the same concept. With an unnamed concept, you may first have to discover how the phenomenon has been represented in the literature.

Use seed articles as evidence about vocabulary

A useful starting point is a small set of records that you already know are relevant. These are often called seed, sentinel, benchmark, or key articles. Examine their titles, abstracts, author keywords, and database subject headings. Look for recurring phrases and unexpected terminology.

Then follow those terms into additional relevant records. New records may expose additional vocabulary, which can in turn be tested. This iterative process is sometimes described as term harvesting or pearl growing.

Cochrane's guidance on search strategy development recommends identifying both free-text terms and appropriate controlled vocabulary and notes that preliminary searching, relevant papers, related reviews, thesauri, and text-mining approaches can help identify candidate terminology.

Search natural language as well as database indexing

Controlled vocabularies such as MeSH can be valuable because they group records under standardized subject concepts even when authors use different wording. However, an unnamed or newly developing concept may not have a dedicated subject heading. It may be indexed under a broader concept, distributed across several headings, or represented differently across databases.

Free-text searching is therefore particularly important. Search terms can target language in titles, abstracts, keywords, and other searchable fields, depending on the database. For systematic reviews of interventions, Cochrane recommends combining appropriate controlled vocabulary with free-text terms rather than relying exclusively on either approach.

The distinction between keywords and subject headings becomes practically important here. A subject heading may provide conceptual stability, while free text can capture terminology that has not yet been standardized.

Build families of expressions, not a flat pile of words

It can help to organize candidate terminology by how each expression represents the concept. You might have direct labels, descriptive phrases, broader labels, narrower manifestations, abbreviations, or relevant indexing terms. This makes it easier to see why each term belongs in the search rather than accumulating dozens of vaguely related words.

Be cautious with related concepts that are not exact synonyms. A term can help retrieve relevant studies without being interchangeable with your target concept, but that relationship should be understood rather than silently treated as equivalence.

Use OR within the concept, but do not let Boolean logic replace conceptual judgment

Once appropriate expressions have been identified, alternatives representing the same search concept are usually combined with OR. Cochrane's technical guidance describes this as the usual approach for combining controlled vocabulary, text words, synonyms, and related terms within a concept. Separate concepts are then generally combined with AND.

A simplified concept block might therefore look like:

("term A" OR "term B" OR "descriptive phrase C" OR "alternative expression D")

But Boolean OR is not evidence that the terms mean the same thing. It merely tells the database that a record containing any of those expressions may qualify for retrieval. The conceptual justification still belongs to the researcher.

Proximity searching can help when the concept is described rather than named

Some concepts appear through combinations of ordinary words rather than a stable phrase. In databases that support proximity operators, you may be able to search for two important words occurring within a specified distance of each other rather than requiring one exact phrase.

This can improve flexibility when authors vary word order or insert modifiers. Syntax differs substantially among databases, however, so the strategy must be translated rather than copied mechanically from one platform to another. Search-strategy guidance likewise emphasizes database-specific adaptation.

Terminology discovery should be iterative

Your first search can be treated partly as reconnaissance. Inspect relevant results. What terminology did authors use that you did not anticipate? Which subject headings were assigned? Which candidate terms retrieve useful records, and which mainly introduce noise?

Text-mining methods can also assist with term discovery by examining vocabulary and patterns in sets of relevant records. Current evidence-synthesis guidance treats these tools as aids to human search development rather than replacements for domain expertise and information-retrieval judgment.

This iterative approach is particularly useful when terminology is still changing around an emerging topic.

Validate against known relevant studies

A search that returns thousands of records is not necessarily comprehensive. One practical check is whether it retrieves records that you already know should be found. If a benchmark article is missing, determine why. Perhaps it uses terminology absent from your strategy, is indexed under an unexpected heading, or describes the concept too indirectly for your current query.

Known-item testing does not prove that every relevant record will be retrieved. It is a diagnostic check. Search quality also depends on the structure of the research question, database coverage, indexing, search syntax, and other design choices. The PRESS guideline, for example, identifies subject headings, text-word searching, Boolean and proximity operators, spelling and syntax among the elements that should be considered when peer reviewing electronic search strategies.

From an unnamed idea to a searchable concept block

The important point is not the particular terms in this hypothetical example. It is the direction of reasoning. You did not decide that your first phrase was the official name and then search outward from it. You defined the phenomenon, observed how the literature represented it, and allowed that evidence to shape the search vocabulary.

Common mistakes when terminology is unsettled

Treat vocabulary development as part of the research method

If your concept has no agreed name, do not ask only, "What keyword should I use?" A better question is, "Through what language could a relevant study represent this concept?" That shift changes search development from guessing synonyms to investigating terminology.

Keep a record of candidate terms and why they were retained, modified, or rejected. For a formal evidence synthesis, this documentation can make the eventual strategy easier to explain, reproduce, update, and peer review.

Before finalizing a search for an unnamed concept

Questions about searching when terminology is unsettled

Search for the idea, not merely its current label

How to Cite This Guide

This guide is intended to be read, shared, and used in research, teaching, and academic work. If you draw on its ideas, explanations, or other content, please acknowledge the source by citing the guide. Doing so gives appropriate credit and helps your readers locate the original resource.