Comprehensive Taxonomy of Research Gaps: A Complete Guide for Researchers
A comprehensive guide to 25 distinct types of research gaps with practical frameworks, identification strategies, and examples for dissertation proposals, grant applications, and journal articles
Identifying research gaps is a fundamental skill for any researcher, yet many struggle to articulate what makes their research novel and necessary. This comprehensive guide presents 25 distinct types of research gaps drawn from established frameworks and emerging research practices. Whether you’re preparing a dissertation proposal, writing a grant application, or crafting a journal article, understanding these gap types will strengthen your research justification.
What is a Research Gap?
A research gap represents an area where knowledge is incomplete, contradictory, or absent in the existing literature. Identifying gaps is not about criticizing previous research—it’s about recognizing opportunities for meaningful contribution to your field.
The Complete Taxonomy: 25 Types of Research Gaps
Classic Research Gaps (Evidence-Based Framework)
1. Evidence Gap (Contradictory Evidence Gap)
Definition: Results from studies allow for conclusions in their own right, but are contradictory when examined from a more abstract point of view.
সংজ্ঞা: বিভিন্ন গবেষণার ফলাফল নিজস্ব দৃষ্টিকোণ থেকে সঠিক হলেও, একটি বিস্তৃত বা তাত্ত্বিক দৃষ্টিকোণ থেকে পর্যালোচনা করলে পরস্পরবিরোধী বা অসামঞ্জস্যপূর্ণ বলে প্রতীয়মান হয়।
Key Indicators:
- Conflicting findings across studies
- Inconsistent results across contexts
- Contradictory conclusions from similar research
| Reference: Müller-Bloch & Kranz (2015) - ResearchGate | Semantic Scholar |
Recent WOS-Indexed Papers (2023-2025):
2. Knowledge Gap (Knowledge Void Gap)
Definition: Desired research findings do not exist—the topic has simply not been studied yet.
সংজ্ঞা: কোনো নির্দিষ্ট বিষয় বা সমস্যা সম্পর্কে গবেষণা এখনও করা হয়নি—জ্ঞানের সম্পূর্ণ অনুপস্থিতি রয়েছে।
Key Indicators:
- Complete absence of research on a topic
- Unexplored phenomena or questions
- New emerging topics without scholarly attention
| Reference: Müller-Bloch & Kranz (2015) - ResearchGate | Semantic Scholar |
Recent WOS-Indexed Papers (2023-2025):
3. Practical Knowledge Gap (Action-Knowledge Conflict Gap)
Definition: Professional behavior or practices deviate from research findings, or practitioners face problems not covered by existing research.
সংজ্ঞা: পেশাদার কর্মপদ্ধতি বা বাস্তব অনুশীলন গবেষণা ফলাফলের সাথে সামঞ্জস্যপূর্ণ নয়, অথবা বাস্তবে যেসব সমস্যার মুখোমুখি হন তা বিদ্যমান গবেষণায় আলোচিত হয়নি।
Key Indicators:
- Theory-practice disconnect
- Practitioner challenges unaddressed in literature
- Real-world problems lacking scholarly investigation
| Reference: Müller-Bloch & Kranz (2015) - ResearchGate | Semantic Scholar |
Recent WOS-Indexed Papers (2023-2025):
4. Methodological Gap (Method and Research Design Gap)
Definition: A variation of research methods is necessary to generate new insights or to avoid distorted findings from methodological limitations.
সংজ্ঞা: নতুন অন্তর্দৃষ্টি অর্জন বা পদ্ধতিগত সীমাবদ্ধতা থেকে বিকৃত ফলাফল এড়াতে গবেষণা পদ্ধতির বৈচিত্র্য বা নতুন গবেষণা নকশা প্রয়োজন।
Key Indicators:
- Limited methodological approaches in existing studies
- Need for mixed methods or alternative designs
- Methodological biases requiring correction
| Reference: Müller-Bloch & Kranz (2015) - ResearchGate | Semantic Scholar |
Recent WOS-Indexed Papers (2023-2025):
5. Empirical Gap (Evaluation Void Gap)
Definition: Research findings or propositions need to be evaluated or empirically verified through data collection and analysis.
সংজ্ঞা: গবেষণার ফলাফল বা প্রস্তাবনাগুলো ডেটা সংগ্রহ এবং বিশ্লেষণের মাধ্যমে মূল্যায়ন বা পরীক্ষামূলকভাবে যাচাই করা প্রয়োজন।
Key Indicators:
- Untested hypotheses or propositions
- Theoretical claims lacking empirical validation
- Conceptual frameworks requiring empirical support
| Reference: Müller-Bloch & Kranz (2015) - ResearchGate | Semantic Scholar |
Recent WOS-Indexed Papers (2023-2025):
6. Theoretical Gap (Theory Application Void Gap)
Definition: Theory should be applied to certain research issues to generate new insights, or there is a lack of theoretical foundation for understanding phenomena.
সংজ্ঞা: নতুন জ্ঞান অর্জনের জন্য নির্দিষ্ট গবেষণা সমস্যায় তত্ত্ব প্রয়োগ করা উচিত, অথবা কোনো ঘটনা বোঝার জন্য তাত্ত্বিক ভিত্তির অভাব রয়েছে।
Key Indicators:
- Atheoretical or under-theorized studies
- Lack of theoretical frameworks
- Opportunities for theory application or development
| Reference: Müller-Bloch & Kranz (2015) - ResearchGate | Semantic Scholar |
Recent WOS-Indexed Papers (2023-2025):
7. Population Gap
Definition: Research regarding populations that are not adequately represented or under-researched in the evidence base (e.g., by gender, race/ethnicity, age, disability status, etc.).
সংজ্ঞা: এমন জনগোষ্ঠী যারা গবেষণায় পর্যাপ্তভাবে প্রতিনিধিত্বহীন বা কম গবেষিত (যেমন: লিঙ্গ, জাতিগত পরিচয়, বয়স, প্রতিবন্ধিতার অবস্থা ইত্যাদি)।
Key Indicators:
- Underrepresented demographic groups
- Demographic imbalances in research samples
- Systematically excluded populations
| Reference: Robinson et al. (2011) - NCBI Bookshelf | PubMed |
Recent WOS-Indexed Papers (2023-2025):
Extended Research Gaps (Contemporary Framework)
8. Geographical/Regional Gap
Definition: Research conducted in certain regions or countries but lacking in others, limiting generalizability across different geographical contexts.
সংজ্ঞা: কিছু নির্দিষ্ট অঞ্চল বা দেশে গবেষণা হয়েছে কিন্তু অন্যান্য স্থানে হয়নি, যা ভৌগোলিক প্রেক্ষাপটে ফলাফলের সাধারণীকরণ সীমিত করে।
Key Indicators:
- Geographic concentration of studies (e.g., North America-centric)
- Western-centric research paradigms
- Regional knowledge voids in Global South
Recent WOS-Indexed Papers (2023-2025):
- DOI: 10.1371/journal.pone.0295505
- DOI: 10.1016/j.geosus.2025.100376
- DOI: 10.1080/23311975.2025.2549511
9. Temporal/Time Gap
Definition: Research from a specific time period that needs updating, or longitudinal studies that haven’t been conducted over extended periods.
সংজ্ঞা: নির্দিষ্ট সময়কালের গবেষণা যা হালনাগাদ করা প্রয়োজন, অথবা দীর্ঘমেয়াদী অনুদৈর্ঘ্য গবেষণা যা এখনও পরিচালিত হয়নি।
Key Indicators:
- Outdated findings requiring contemporary examination
- Historical period-specific focus
- Lack of longitudinal data
Recent WOS-Indexed Papers (2023-2025):
10. Contextual Gap
Definition: Research findings from one context (e.g., corporate settings) not validated in other contexts (e.g., non-profit, education, healthcare).
সংজ্ঞা: একটি নির্দিষ্ট প্রেক্ষাপটে (যেমন: কর্পোরেট) প্রাপ্ত গবেষণা ফলাফল অন্য প্রেক্ষাপটে (যেমন: অলাভজনক, শিক্ষা, স্বাস্থ্যসেবা) যাচাই করা হয়নি।
Key Indicators:
- Context-specific limitations acknowledged but unaddressed
- Limited transferability across sectors
- Single-sector research dominance
Recent WOS-Indexed Papers (2023-2025):
11. Application/Implementation Gap
Definition: Theoretical research exists but lacks practical application studies or real-world implementation evidence.
সংজ্ঞা: তাত্ত্বিক গবেষণা বিদ্যমান কিন্তু ব্যবহারিক প্রয়োগ গবেষণা বা বাস্তব বাস্তবায়নের প্রমাণ অনুপস্থিত।
Key Indicators:
- Theory without practice
- Implementation challenges unstudied
- Adoption barriers unknown
Recent WOS-Indexed Papers (2023-2025):
12. Technology/Digital Gap
Definition: Lack of research on emerging technologies or digital transformations in established fields.
সংজ্ঞা: উদীয়মান প্রযুক্তি বা প্রতিষ্ঠিত ক্ষেত্রে ডিজিটাল রূপান্তর সম্পর্কে গবেষণার অভাব।
Key Indicators:
- New technology emergence
- Digital disruption unaddressed
- AI, blockchain, IoT phenomena unstudied in specific contexts
Recent WOS-Indexed Papers (2023-2025):
13. Interdisciplinary Gap
Definition: Absence of cross-disciplinary research combining multiple fields to address complex problems.
সংজ্ঞা: জটিল সমস্যা সমাধানে একাধিক বিষয়ের সমন্বয়ে আন্তঃবিষয়ক গবেষণার অনুপস্থিতি।
Key Indicators:
- Siloed disciplinary research
- Lack of integration across fields
- Multi-field perspectives needed
Recent WOS-Indexed Papers (2023-2025):
14. Scale Gap
Definition: Research at one level of analysis (micro/macro) without corresponding studies at other levels (e.g., individual vs. organizational level).
সংজ্ঞা: একটি বিশ্লেষণ স্তরে (যেমন: ব্যক্তিগত বা সাংগঠনিক) গবেষণা হয়েছে কিন্তু অন্য স্তরে সংশ্লিষ্ট গবেষণা নেই।
Key Indicators:
- Single-level analysis predominance
- Micro-macro divide
- Multi-level studies needed
Recent WOS-Indexed Papers (2023-2025):
15. Measurement/Instrumentation Gap
Definition: Lack of validated instruments, metrics, or assessment tools for measuring specific constructs or phenomena.
সংজ্ঞা: নির্দিষ্ট ধারণা বা ঘটনা পরিমাপের জন্য বৈধ উপকরণ, মেট্রিক্স বা মূল্যায়ন সরঞ্জামের অভাব।
Key Indicators:
- No standard measures available
- Measurement validity or reliability issues
- Scale development needed
Recent WOS-Indexed Papers (2023-2025):
16. Cultural Gap
Definition: Research dominated by Western or specific cultural perspectives, lacking cross-cultural validation or indigenous knowledge.
সংজ্ঞা: পশ্চিমা বা নির্দিষ্ট সাংস্কৃতিক দৃষ্টিভঙ্গির প্রাধান্য রয়েছে এমন গবেষণা, যেখানে আন্তঃসাংস্কৃতিক যাচাইকরণ বা স্থানীয় জ্ঞানের অভাব রয়েছে।
Key Indicators:
- Cultural bias in theories or measures
- Limited cultural diversity in samples
- WEIRD (Western, Educated, Industrialized, Rich, Democratic) sample dominance
Recent WOS-Indexed Papers (2023-2025):
17. Process Gap
Definition: Understanding of outcomes exists but the processes or mechanisms leading to those outcomes are unclear.
সংজ্ঞা: ফলাফল সম্পর্কে ধারণা আছে কিন্তু সেই ফলাফলে পৌঁছানোর প্রক্রিয়া বা পদ্ধতি অস্পষ্ট।
Key Indicators:
- Black box phenomena
- Unknown causal mechanisms
- “How” questions unanswered
Recent WOS-Indexed Papers (2023-2025):
18. Longitudinal Gap
Definition: Predominantly cross-sectional studies with insufficient long-term longitudinal research.
সংজ্ঞা: প্রধানত প্রস্থচ্ছেদ গবেষণা রয়েছে কিন্তু দীর্ঘমেয়াদী অনুদৈর্ঘ্য গবেষণার অপর্যাপ্ততা।
Key Indicators:
- Snapshot research only
- Temporal dynamics unstudied
- Developmental processes unknown
Recent WOS-Indexed Papers (2023-2025):
19. Comparative Gap
Definition: Lack of comparative studies across different groups, contexts, or conditions.
সংজ্ঞা: বিভিন্ন দল, প্রেক্ষাপট বা শর্তের মধ্যে তুলনামূলক গবেষণার অভাব।
Key Indicators:
- Single-case focus
- No benchmarking or comparison studies
- Cross-national or cross-sector comparisons needed
Recent WOS-Indexed Papers (2023-2025):
20. Replication Gap
Definition: Original findings not replicated or validated through independent studies, raising questions about reproducibility.
সংজ্ঞা: মূল ফলাফলগুলো স্বাধীন গবেষণার মাধ্যমে পুনরাবৃত্তি বা যাচাই করা হয়নি, যা পুনরুৎপাদনযোগ্যতা নিয়ে প্রশ্ন উত্থাপন করে।
Key Indicators:
- Unreplicated results
- Single-study phenomena
- Reproducibility concerns
| Reference: Open Science Collaboration (2015) - PubMed | ResearchGate |
Recent WOS-Indexed Papers (2023-2025):
21. Integration Gap
Definition: Fragmented research findings that haven’t been synthesized or integrated into coherent frameworks.
সংজ্ঞা: বিচ্ছিন্ন গবেষণা ফলাফল যা সুসংগত কাঠামোতে সংশ্লেষিত বা একীভূত করা হয়নি।
Key Indicators:
- Scattered literature
- Lack of meta-analyses or systematic reviews
- Synthesis needed
Recent WOS-Indexed Papers (2023-2025):
22. Stakeholder Gap
Definition: Research conducted from limited stakeholder perspectives, missing voices of key groups affected by the phenomenon.
সংজ্ঞা: সীমিত স্টেকহোল্ডার দৃষ্টিভঙ্গি থেকে পরিচালিত গবেষণা, যেখানে ঘটনা দ্বারা প্রভাবিত মূল গোষ্ঠীগুলোর কণ্ঠস্বর অনুপস্থিত।
Key Indicators:
- Single perspective studies (e.g., only management views)
- Excluded stakeholder voices
- Multi-stakeholder analysis needed
Recent WOS-Indexed Papers (2023-2025):
23. Causal Mechanism Gap
Definition: Correlational relationships established but underlying causal mechanisms unexplored.
সংজ্ঞা: পারস্পরিক সম্পর্ক প্রতিষ্ঠিত হয়েছে কিন্তু অন্তর্নিহিত কার্যকারণ পদ্ধতি অনুসন্ধান করা হয়নি।
Key Indicators:
- Association without causation
- Mediating or moderating processes unknown
- Mechanism understanding lacking
Recent WOS-Indexed Papers (2023-2025):
24. Boundary Condition Gap
Definition: Research findings established but boundaries of applicability (when/where/for whom) remain unclear.
সংজ্ঞা: গবেষণা ফলাফল প্রতিষ্ঠিত কিন্তু প্রয়োগযোগ্যতার সীমানা (কখন/কোথায়/কার জন্য) অস্পষ্ট রয়ে গেছে।
Key Indicators:
- Undefined scope of theories
- Moderating factors unknown
- Generalization limits unclear
Recent WOS-Indexed Papers (2023-2025):
25. Impact Gap
Definition: Research conducted but long-term impacts, consequences, or implications not assessed.
সংজ্ঞা: গবেষণা পরিচালিত হয়েছে কিন্তু দীর্ঘমেয়াদী প্রভাব, পরিণতি বা প্রভাবসমূহ মূল্যায়ন করা হয়নি।
Key Indicators:
- Short-term focus only
- Downstream effects unstudied
- Societal or practical impact evaluation missing
Recent WOS-Indexed Papers (2023-2025):
- DOI: 10.3389/fclim.2025.1534267
- DOI: 10.1007/s10671-022-09321-4
- DOI: 10.1016/j.technovation.2023.102817
How to Identify Research Gaps: A Systematic Approach
1. Conduct a Thorough Literature Review
Start with systematic scanning of your field:
- Read limitations sections in published papers
- Look for “future research” recommendations
- Note methodological constraints acknowledged by authors
- Observe contradictory findings across studies
Pro Tip: Use reference management software like Zotero or Mendeley to tag papers by gap type as you read.
2. Monitor Emerging Phenomena
Stay alert to changes in your field:
- Track new technologies (AI, blockchain, quantum computing)
- Observe social changes (remote work, demographic shifts)
- Follow policy developments (regulations, laws)
- Identify industry disruptions (new business models)
Resource: Set up Google Scholar alerts for key terms in your field.
3. Engage with Practitioners
Bridge the research-practice divide:
- Interview industry professionals
- Attend practitioner conferences (not just academic ones)
- Review trade publications and industry reports
- Analyze real-world problems facing professionals
Insight: Practical knowledge gaps often yield the most impactful research.
4. Examine Theoretical Development
Look at your field’s theoretical landscape:
- Study theory evolution over time
- Identify untested propositions in established theories
- Look for theory application opportunities in new contexts
- Find theoretical conflicts or competing explanations
5. Consider Methodological Innovation
Assess how research is being conducted:
- Evaluate available methods in your field
- Consider new analytical tools (machine learning, NLP, network analysis)
- Explore mixed-method possibilities
- Identify measurement challenges
Strategies for Addressing Research Gaps
Priority Assessment Framework
Before committing to a research gap, evaluate it using these criteria:
| Criterion | Key Questions |
|---|---|
| Significance | How important is this gap to theory and practice? |
| Feasibility | Can it be addressed with available resources, data, and time? |
| Novelty | How unique is this research opportunity? |
| Impact | What contribution will filling this gap make? |
| Alignment | Does it fit your expertise and research program? |
Research Design Considerations
Once you’ve identified a gap:
- Match methodology to gap type (qualitative for process gaps, quantitative for population gaps, etc.)
- Consider resource requirements (time, funding, access)
- Plan appropriate timeline (longitudinal gaps require years)
- Address ethical considerations (especially for population gaps)
- Ensure practical relevance (stakeholder engagement)
Common Pitfalls to Avoid
1. Artificial Gap Creation
Problem: Manufacturing gaps where none meaningfully exist.
Solution: Ensure your gap addresses a genuine need in the literature.
2. Overgeneralization
Problem: Claiming broader gaps than evidence supports.
Solution: Be specific about the scope and boundaries of your gap.
3. Ignoring Practical Significance
Problem: Gaps that matter only for academic curiosity.
Solution: Connect your gap to real-world implications.
4. Methodological Mismatch
Problem: Wrong research approach for the gap type.
Solution: Align your methods with the nature of the gap.
5. Scope Overreach
Problem: Trying to fill too many gaps at once.
Solution: Define manageable, focused research questions.
Crafting Your Gap Statement: Practical Framework
The Four-Part Structure
Every strong gap statement follows this progression:
Part 1: Establish Current Knowledge
What researchers already know about your topic.
Example:
“Research on student engagement has identified key factors including instructor presence, peer interaction, and course design (Smith et al., 2020; Jones, 2021). Studies consistently show positive correlations between these factors and learning outcomes.”
Part 2: Identify the Gap
Specify exactly what’s missing and provide evidence.
Example:
“However, these studies have predominantly examined traditional face-to-face contexts (87% of reviewed studies), leaving a contextual gap regarding online learning environments. Furthermore, a process gap exists—while we know that instructor presence correlates with engagement, the mechanisms by which this relationship develops over time remain unclear.”
Part 3: Justify Significance
Explain why this gap matters.
Example:
“Given that online enrollment has grown 300% in the past five years, understanding engagement in digital contexts is critical for educational policy and practice. Identifying the process mechanisms will enable evidence-based interventions rather than correlation-based assumptions.”
Part 4: Propose Your Solution
State your research questions and approach.
Example:
“This study addresses these gaps by examining instructor-student interactions in online courses over one semester using a mixed-methods longitudinal design. We ask: (1) How does instructor presence influence student engagement in online contexts? (2) What mechanisms mediate this relationship? (3) How do these processes unfold over time?”
Multi-Gap Analysis: Addressing Multiple Gaps
Research often addresses multiple gap types simultaneously. This strengthens your justification.
Example: AI Adoption in Healthcare
Primary Gap: Technology Gap (AI applications in diagnosis)
Secondary Gaps:
- Contextual Gap (healthcare-specific implementation)
- Practical Gap (real-world adoption challenges)
- Process Gap (how adoption occurs over time)
- Stakeholder Gap (perspectives of doctors, patients, administrators)
Strategy:
- Identify your primary gap (main research focus)
- Recognize secondary gaps (additional contributions)
- Show interconnections (how gaps relate)
- Prioritize clearly (which takes precedence)
Gap Evolution: Staying Current
Research gaps are dynamic, not static:
- New gaps emerge with technological and social changes
- Some gaps get filled through research progress
- Gaps shift in importance and priority over time
- Interdisciplinary gaps become increasingly prominent
How to Stay Current:
- Monitor recent publications (last 2-3 years)
- Attend academic conferences (presentations on cutting-edge work)
- Follow research trends (rising topics in your field)
- Engage with research communities (Twitter, ResearchGate, LinkedIn)
- Track emerging phenomena (news, industry reports, policy changes)
Key References with DOI Links
Foundational Framework
Methodological Advances
Cross-Cultural Research
Replication and Reproducibility
Theory Development
Practical Tips for Researchers
For Doctoral Students
- Start broad, narrow systematically – Identify multiple gaps, then focus on the most feasible
- Consult your committee early – Get feedback on gap significance
- Document your gap identification process – Show systematic literature review
- Connect to your field’s priorities – Align with journals and funding agencies
For Grant Writers
- Emphasize practical significance – Show real-world impact
- Use multiple gap types – Strengthen justification
- Cite funding agency priorities – Show alignment with mission
- Include preliminary data – Demonstrate feasibility
For Journal Article Authors
- Be explicit and specific – Don’t assume reviewers see the gap
- Connect to theory – Show theoretical contribution
- Address “so what?” question – Explain significance clearly
- Anticipate reviewer concerns – Justify your choices
Conclusion
Identifying research gaps is both an art and a science. This comprehensive taxonomy provides a systematic framework for recognizing opportunities for scholarly contribution. Remember:
- Not all gaps are created equal – prioritize significance and feasibility
- Multiple gaps strengthen your argument – but maintain clear focus
- Gaps evolve – stay current with your field
- Think beyond your discipline – interdisciplinary gaps offer rich opportunities
- Be bold but realistic – ambitious goals with achievable methods
The ability to articulate a clear, compelling research gap is fundamental to successful scholarship. Use this guide as a reference throughout your research journey.
Quick Reference Summary
25 Research Gap Types:
Classic Framework (1-7): Evidence | Knowledge | Practical Knowledge | Methodological | Empirical | Theoretical | Population
Extended Framework (8-25): Geographical | Temporal | Contextual | Application | Technology | Interdisciplinary | Scale | Measurement | Cultural | Process | Longitudinal | Comparative | Replication | Integration | Stakeholder | Causal Mechanism | Boundary Condition | Impact
Last Updated: January 19, 2026 Source Frameworks: Müller-Bloch & Kranz (2015), Robinson et al. (2011), Multiple Contemporary Sources
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