Manuel B. Garcia

Manuel B. Garcia serves as the Senior Director for Educational Technology and Digital Learning at FEU Institute of Technology, Manila, Philippines. Read More

Contact Info

1607, FEU Tech Building,
P. Paredes St, Sampaloc,
Manila, Philippines
mbgarcia@feutech.edu.ph

Follow Me

Part 2 · Guide 137 of 899

What Should You Do When Your Concept Is Too Broad to Search Effectively?

When a concept is too broad, adding more search terms may only create a larger and less coherent query. Clarify what the concept means in your study before trying to make the database solve the problem.

By Manuel B. Garcia
137
When a Concept Is Too Broad to Search Guide 137 of 899
01 · The Question

What If the Problem Is the Concept Rather Than the Search Terms?

Sometimes a literature search keeps producing an enormous and conceptually scattered set of papers even after you have adjusted keywords, phrases, fields, and Boolean operators. The problem may be upstream of the database: the concept itself covers too many different phenomena.

Terms such as technology, learning, well-being, innovation, quality, or performance can represent legitimate research concepts, but each can also encompass several distinct meanings, populations, settings, mechanisms, and outcomes.

A database cannot decide which of those meanings belongs in your study. If you have not established the conceptual boundaries first, attempts to "fix" the search may amount to arbitrary narrowing rather than defensible search design.

02 · The Short Answer

Define the Concept Before You Try to Narrow the Query

In Brief

If a concept is too broad to search effectively, clarify what the concept includes and excludes in relation to your research question, identify its major dimensions or sub-concepts, and then search the dimensions that actually represent your intended evidence.

Do not narrow the search merely by adding convenient terms until the result count looks manageable. The boundaries should come from the research question, eligibility criteria, conceptual literature, and terminology used in the field rather than from the number of records you would prefer to screen.

03 · What You Need to Know

Broad Search Results Can Reveal an Underdefined Concept

Distinguish a broad topic from a broad search term

These are related but different problems.

Broad search term One word or expression retrieves material outside the concept you already understand clearly.
Broad concept The construct itself encompasses several meanings or forms, and you have not yet determined which belong in the study.

If technology is merely an imprecise synonym for a clearly defined concept such as learning management systems, the problem may be solved at the term level. If your study genuinely concerns "technology in education" but you cannot say whether that includes administrative systems, virtual reality, artificial intelligence, learning analytics, mobile devices, social media, or laboratory equipment, the conceptual scope needs attention first.

When only one unusually broad term is overwhelming an otherwise coherent strategy, troubleshoot that term before redefining the concept.

Write an operational boundary for the concept

Before generating more synonyms, try to state what qualifies as an instance of the concept for this particular study.

A useful boundary might answer questions such as:

  • What phenomenon must be present?
  • Which closely related phenomena count?
  • Which apparently similar phenomena do not count?
  • Does the concept refer to an intervention, experience, behavior, outcome, setting, technology, process, or something else?
  • Would two independent reviewers be able to apply the boundary consistently when screening a paper?

This is not merely a search exercise. It connects the retrieval strategy to the eligibility criteria. If you cannot determine whether a paper belongs conceptually after reading it, the database query is unlikely to resolve that ambiguity for you.

Map the concept into meaningful dimensions

A broad concept often becomes searchable once you identify how it is structured.

Suppose the topic is digital learning. Depending on the research question, that umbrella could encompass online learning, blended learning, mobile learning, learning management systems, educational applications, virtual environments, and other technology-mediated forms of instruction.

The purpose of concept mapping is not to include every related term. It is to expose the structure of the concept so that you can decide which branches genuinely belong within scope.

Those branches can then inform free-text terminology, controlled-vocabulary exploration, and eligibility criteria.

Do not mistake narrower terminology for a narrower research question

You can make almost any search smaller by using more specific words. That does not mean you have represented the intended research question correctly.

If the research question concerns all forms of educational technology but the search is restricted to "learning management system" because that produces a convenient number of records, the search has not merely become more precise. The substantive scope has changed.

Search precision should come from representing the intended concept accurately, not silently redefining it.

Use existing terminology and controlled vocabularies to understand conceptual structure

Controlled vocabularies can be useful not only for executing searches but also for examining how a field organizes concepts. MeSH, for example, is hierarchical: descriptors can be examined from broader to narrower positions in its tree structure. The National Library of Medicine also provides scope information and entry terminology that can help clarify what a descriptor represents.

Other disciplinary databases have their own thesauri or subject-heading systems. These structures do not dictate your theoretical definition, but they can reveal distinctions, narrower concepts, and terminology worth considering.

Controlled vocabularies also evolve. The National Library of Medicine notes that MeSH is continually updated and adds new concepts as terminology and fields develop. This matters when a broad contemporary concept contains newer subfields that may not have been represented historically in the same way.

Search the literature iteratively to learn its vocabulary

Early searching can be exploratory. Identify a few highly relevant papers, inspect how they describe the concept, examine their indexing terms, and follow useful terminology into additional records.

This creates a productive loop:

Define State your current understanding of the concept and its boundaries.
Search Use preliminary terms to find representative literature.
Inspect Study terminology, indexing, and conceptual distinctions in relevant records.
Refine Revise the concept map and search vocabulary when the literature reveals defensible distinctions you had not anticipated.

Iteration is particularly important when the topic itself has no stable terminology. In that situation, the conceptual boundary may be clearer than the words authors use to describe it.

Do not put every aspect of the research question into the search

Once researchers recognize that a concept is broad, one reaction is to add more required concepts with AND. That certainly reduces retrieval, but it can reduce sensitivity as well.

Cochrane advises that bibliographic search strategies should be structured around the main concepts of a review and notes that searching every aspect of the clinical question may be unnecessary or undesirable. Some characteristics, such as particular outcomes or comparators, may be inconsistently described in titles, abstracts, or controlled vocabulary.

The exact structure depends on the question and discipline, but the general lesson travels well: eligibility criteria and database search concepts are related without being identical. Some criteria are better applied during screening than encoded as mandatory search terms.

Decide whether the breadth is actually a problem

A concept can be broad because the research question is intentionally broad. A scoping review, evidence map, or exploratory project may legitimately examine a wide conceptual territory.

In such cases, a large heterogeneous result set may reflect the purpose of the study rather than poor search design. Narrowing it solely for convenience could undermine that purpose.

The appropriate question is whether the retrieved breadth corresponds to your intended scope. If it does, the solution may involve managing the screening workload rather than narrowing the concept.

Watch Out

Do not let the database determine the scope of the study by trial and error. "We narrowed the concept because 20,000 results seemed too many" is a workload decision, not a conceptual justification. If feasibility requires a narrower study, revise the research scope explicitly and justify that decision.

Sometimes the research question needs revision

If you cannot define the concept without including several fundamentally different phenomena, the search may be exposing a problem in the research question itself.

That is not a failure. Preliminary searching is partly a feasibility test. It can show that an apparently coherent topic is too heterogeneous for the intended design, available time, or analytic purpose.

The defensible response may be to narrow the population, phenomenon, setting, intervention, outcome, or other substantive boundary and then reformulate the search around the revised question.

04 · A Practical Example

Turn an Umbrella Concept Into Searchable Boundaries

Hypothetical Example

"Technology use" among university students is too broad

A researcher initially plans to study the effects of technology use on university students. A preliminary search retrieves literature on smartphones, social media, artificial intelligence, learning management systems, virtual reality, assistive technologies, laboratory equipment, online learning, administrative platforms, and general internet use.

Diagnose the problem The researcher realizes that the search is not simply suffering from poor keywords. "Technology use" itself has not been conceptually bounded.
Return to the research purpose The intended interest is technology used directly by students to support formal learning activities, rather than every technology encountered within a university.
Establish boundaries The researcher defines which forms of student-facing learning technology fall within scope and distinguishes them from administrative systems, general personal technology use, and equipment unrelated to learning activities.
Map the included concept Relevant forms of learning technology and their terminology are identified from conceptual literature, known studies, database subject headings, and exploratory searches.
Rebuild and test The revised search represents the clarified concept and is tested against relevant papers. The result set becomes more coherent because the research scope is more coherent, not simply because arbitrary restrictions were added.

The reduction in retrieval is a consequence of conceptual clarification. That is methodologically different from repeatedly adding AND terms until the database produces a convenient number.

05 · What Researchers Often Get Wrong

Common Mistakes When a Concept Is Too Broad

Misconception

"I just need more specific keywords."

Sometimes you do. But if you cannot explain which manifestations of the broader concept belong in the study, choosing narrower words merely makes an unresolved conceptual decision inside the search string.

Misconception

"The search is too broad because it retrieves too many papers."

Result count alone cannot establish this. A broad research question may legitimately have a large literature. Examine whether the records fall within the intended conceptual scope rather than judging the search from quantity alone.

Misconception

"Adding another concept with AND will fix it."

It will usually reduce retrieval, but the new requirement may exclude relevant papers. Add a concept because the research question requires it and because it can be represented appropriately in searchable records, not merely because you want fewer results.

Misconception

"A controlled-vocabulary heading gives me the correct definition."

A thesaurus tells you how a database organizes and indexes concepts. That can be highly informative, but it does not replace the theoretical or operational definition required by your particular research question.

Misconception

"If narrowing makes screening easier, the search has improved."

Feasibility matters, but a smaller workload is not itself evidence of better retrieval. If you narrow the substantive scope for practical reasons, make that an explicit study-design decision rather than hiding it inside the query.

06 · What This Means for You

Clarify Scope Before You Engineer a More Restrictive Search

When a concept seems unsearchably broad, move temporarily away from the query box. Define the phenomenon, examine its dimensions, determine what belongs outside the boundary, and compare that definition with the terminology and indexing used in relevant literature.

A simple decision framework

If the concept is clear but one term retrieves unrelated meanings
Keep the conceptual scope and troubleshoot the problematic term rather than narrowing the study.
If several fundamentally different phenomena could all qualify
Define the concept more explicitly and decide which dimensions genuinely belong in the research question.
If the breadth is intentional
Accept that a sensitive search may be large and plan the search and screening process accordingly.
If the intended scope is infeasible
Narrow the research question explicitly and align the eligibility criteria and search strategy with the revised scope.
If the concept is genuinely new
Do not expect controlled vocabularies to solve the terminology problem automatically. Consider how to search when a concept is too new for established subject headings.

If repeated revisions still fail to produce a coherent strategy, another pair of eyes may be more valuable than another hour of Boolean surgery. A research librarian or information specialist can review the conceptual structure and its translation into database syntax, particularly for systematic or otherwise consequential searches.

07 · A Quick Checklist

What to Check Before Narrowing a Broad Concept

Before adding more restrictions, check:
Write a working definition of the concept that explains what qualifies for this study.
Identify closely related phenomena that should fall outside the study's conceptual boundary.
Map meaningful dimensions or sub-concepts rather than generating an undifferentiated list of synonyms.
Inspect terminology and indexing in representative relevant papers.
Explore the relevant database thesaurus or controlled vocabulary for broader, narrower, and related concepts.
Check whether every concept joined with AND genuinely needs to be represented in the database search.
Distinguish substantive narrowing from changes made only to reduce the screening workload.
Test the revised strategy against known relevant papers and inspect whether the resulting literature matches the intended conceptual scope.
08 · Frequently Asked Questions

Questions About Concepts That Are Too Broad to Search

How do I know whether my concept or just my keyword is too broad?

Ask whether you can clearly describe what belongs inside and outside the concept without referring to search terms. If the boundary is clear and one word merely retrieves unrelated meanings, you probably have a terminology problem. If the boundary itself is unclear, the conceptual scope needs work.

Should I narrow the concept if I retrieve thousands of papers?

Not on that basis alone. Determine whether those papers represent the literature your research question actually covers. A large result set may be legitimate, particularly for broad or exploratory questions.

Can I use more AND terms to make a broad concept manageable?

Only when those concepts are substantively required and suitable for database searching. Adding mandatory concepts solely to reduce retrieval can cause relevant records to disappear.

Should eligibility criteria and search terms be identical?

No. Eligibility criteria determine which studies ultimately qualify, while search terms are a retrieval mechanism. Some eligibility characteristics are not consistently represented in searchable metadata and may be better assessed during screening.

What if the concept contains several legitimate sub-concepts?

Map them explicitly and decide whether the research question genuinely encompasses all of them. If it does, the search may need to represent that breadth. If only some dimensions serve the research purpose, define and justify the narrower scope.

What if no consistent terminology exists for the concept?

Separate conceptual definition from terminology. You may know what phenomenon qualifies even when authors call it different things. In that case, build terminology iteratively from relevant records, indexing systems, related concepts, and older or disciplinary language.

Can a librarian help me define the concept?

An information specialist can help translate conceptual boundaries into searchable structures, identify vocabulary and database features, and expose ambiguities in the strategy. The substantive definition itself still needs to be grounded in the research question and relevant disciplinary or theoretical literature.

09 · The Bottom Line

A Broad Search May Be Telling You That the Concept Needs Work

The Bottom Line

When a concept is too broad to search effectively, define its boundaries and meaningful dimensions before trying to force the result count down with narrower keywords, extra AND conditions, or arbitrary filters.

The database should operationalize the scope of your research question, not decide that scope for you. Once the concept is clear, terminology, controlled vocabulary, field restrictions, and Boolean structure become tools for representing that decision rather than substitutes for making it.

10 · Sources and Further Reading

Sources and Further Reading

11 · Cite this Guide

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.

Has the Field Guide helped your research?

If a guide helped clarify a question, inform a research decision, or move your work forward, I would love to hear about your experience. Your story may also help other researchers discover the Field Guide.

Share Your Experience
Takes only a few minutes