From Chaos to System
Yesterday, we identified the problem: most PhD scholars search for papers randomly, relying on Google Scholar, a single database, or forwarded PDFs.
Today, we solve it.
The goal isn’t to find some papers—it’s to build a systematic, repeatable, and defensible literature search strategy.
The Three-Database Rule
Don’t rely on a single source. Research databases have different coverage, indexing, and bias.
Minimum requirement: Search at least three academic databases.
Recommended Combination:
- Scopus (multidisciplinary, citation tracking)
- Web of Science (established journals, high-impact research)
- IEEE Xplore / PubMed / ACM Digital Library (domain-specific)
If institutional access is limited, add:
- Google Scholar (broad coverage, gray literature)
- arXiv / bioRxiv / TechRxiv (preprints in your field)
- Semantic Scholar (AI-powered recommendations)
Why three? Each database has unique indexing. A systematic search reveals papers that single-database searches miss.
What If You Don’t Have Institutional Access?
Use these free alternatives:
- Google Scholar (free, comprehensive)
- CORE (free, open access papers)
- BASE (Bielefeld Academic Search Engine)
- Microsoft Academic (being sunset but archives remain)
- Directory of Open Access Journals (DOAJ)
- ResearchGate / Academia.edu (request papers from authors)
Most preprint servers (arXiv, bioRxiv, SSRN) are completely free.
The Search String: Your Research Fingerprint
Random keyword searches are not systematic. A well-constructed search string ensures consistency and repeatability.
Basic Structure:
(Keyword1 OR Synonym1 OR Related1)
AND
(Keyword2 OR Synonym2 OR Related2)
AND NOT
(Exclusion1 OR Exclusion2)
Example: PhD Research on Educational Technology
Poor search: > “AI in education”
Systematic search:
("artificial intelligence" OR "machine learning" OR "deep learning")
AND
("education" OR "learning" OR "pedagogy" OR "teaching")
AND NOT
("medical education" OR "clinical training")
Why This Matters:
- OR expands search (captures synonyms)
- AND narrows focus (finds intersection)
- NOT removes noise (excludes irrelevant domains)
Document your search string. You’ll need it for reproducibility and thesis methodology chapters.
Database-Specific Syntax
Each database has slightly different syntax:
| Database | Example Search |
|---|---|
| Scopus | TITLE-ABS-KEY("machine learning" AND education) |
| Web of Science | TS=("machine learning" AND education) |
| IEEE Xplore | ("All Metadata":"machine learning" AND "All Metadata":education) |
| PubMed | ("machine learning"[Title/Abstract] AND education[Title/Abstract]) |
| Google Scholar | allintitle: machine learning education |
Check each database’s advanced search help page for exact syntax.
The Search Documentation Template
A systematic search isn’t complete without documentation.
Record These Details:
| Field | Example |
|---|---|
| Database | Scopus |
| Search String | ("literature review" OR "systematic review") AND ("PhD" OR "doctoral") |
| Date Searched | 2026-01-03 |
| Results Found | 347 papers |
| Date Range Filter | 2015–2025 |
| Language Filter | English |
| Document Type | Journal articles, conference papers |
Why document this?
- Repeatability: Someone else can replicate your search
- Thesis requirement: Many universities require search methodology
- Literature review updates: Re-run the search before submission
Pro tip: Keep a dedicated spreadsheet or document tracking all your searches across databases. You’ll thank yourself later when writing your methodology chapter.
Setting Up Citation Alerts
Don’t search manually every few months. Automate it.
For New Papers:
Google Scholar Alerts:
- Run your search in Google Scholar
- Click “Create alert” (bottom left)
- Receive weekly emails with new papers
Database-Specific Alerts:
- Scopus: Save search → Create alert
- Web of Science: Save search → Create citation alert
- IEEE Xplore: Saved searches → Email alerts
RSS Feeds:
- Most journals offer RSS feeds for new issues
- Use an RSS reader (Feedly, Inoreader) to track multiple journals
For Citations to Your Work:
Set up alerts for papers citing:
- Your published work
- Key papers in your field
- Your supervisor’s papers
This keeps you aware of new developments without manual searching.
Filtering Strategy: The Funnel Approach
You’ll get hundreds (or thousands) of results. Don’t try to read everything.
Step 1: Title Screening
- Read titles
- Remove obviously irrelevant papers
- Goal: Reduce by ~70%
Step 2: Abstract Screening
- Read abstracts of remaining papers
- Check alignment with research questions
- Goal: Reduce by another ~60%
Step 3: Full-Text Review
- Read remaining papers fully
- Extract key insights, methods, findings
- Goal: Keep papers directly relevant to your work
Step 4: Citation Snowballing
- Check references of key papers (backward snowballing)
- Check papers citing your key papers (forward snowballing)
- Goal: Discover foundational and recent work
The Inclusion/Exclusion Criteria
Define before searching what papers you’ll include or exclude.
Example Criteria:
Inclusion:
- Published between 2015–2025
- Peer-reviewed journals or top-tier conferences
- Empirical studies with clear methodology
- English language
Exclusion:
- Opinion pieces without data
- Studies outside your geographic/domain scope
- Duplicate publications
- Predatory journals
Document these criteria. They justify why some papers were kept and others discarded.
Common Mistakes to Avoid
❌ Mistake 1: Searching Once and Stopping
Literature keeps growing. Schedule periodic re-searches (e.g., every 3 months).
❌ Mistake 2: Not Using Boolean Operators
“AI education” ≠ “AI AND education”. Learn Boolean logic.
❌ Mistake 3: Ignoring Gray Literature
Theses, technical reports, preprints—sometimes these contain insights published papers don’t.
❌ Mistake 4: No Version Control
Document which version of the search you ran. Database algorithms change over time.
❌ Mistake 5: Using Only English Keywords
If your research has global relevance, consider searching in other languages or using translated keywords.
Time Expectations: Be Realistic
Initial systematic search: 4-8 hours
Title screening (500 papers): 2-3 hours
Abstract screening (150 papers): 3-5 hours
Full-text review (40 papers): 8-12 hours
Total for initial search and screening: 18-28 hours spread over 1-2 weeks.
This seems long, but it prevents the 50+ hours lost to disorganized re-searching later.
What This Achieves
A systematic search ensures:
✅ Completeness: You didn’t miss foundational papers
✅ Transparency: Others can verify your process
✅ Defensibility: You can justify paper selection to supervisors/reviewers
✅ Efficiency: You avoid re-searching from scratch later
What Comes Next
Now you have papers. Hundreds of PDFs sitting in a folder. You now know how to search systematically. You have search strings, filtered results, and documentation.
But here’s the gap: Those papers are still scattered across database interfaces. Some are bookmarked. Some are in browser tabs. None are organized.
The next problem: How do you capture, export, and store these papers so you can actually use them?
In the next post, we’ll tackle:
- Export formats: RIS, BibTeX, CSV—what they mean and which to use
- Reference managers: Choosing between Zotero, Mendeley, EndNote
- File naming systems: So you can find papers 6 months later
- Folder structures: That scale from 50 to 500 papers
- Metadata management: Why it matters more than PDFs
Searching systematically is step one. Storing systematically is what makes the search worthwhile.
A systematic search finds the papers. A systematic storage system makes sure you can use them.
Citation
@online{kumar_nag2026,
author = {Kumar Nag, Prashant},
title = {Building {Your} {Research} {Library:} {The} {Systematic}
{Search} {Framework}},
date = {2026-01-03},
url = {https://prashantnag.com/ResearchInfuser/2026/01/03/research-library-guide/},
langid = {en}
}