RESEARCH FUNDAMENTALS

Common Mistakes Beginners Make in Research

Guide · 2 min read · Last updated 2026-10-31

Beginners often make the same avoidable mistakes: choosing an unfocused question, skipping the protocol, ignoring ethics, collecting data without a plan, using the wrong analysis, and overstating conclusions. Knowing them in advance saves months of work.

Frequent mistakes and fixes

Mistake	Why it matters	Fix
Question too broad	Cannot be answered with one study	Narrow with PICO; one primary outcome
No written protocol	Outcomes and analysis drift	Write a short protocol first
Starting data collection before ethics decision	May invalidate the project	Ask the ethics board early
Undefined variables	Inconsistent data	Create a data dictionary
Many tests, report the "significant" one	False positives	Pre-specify primary analysis
Claiming causation from association	Misleading	Use cautious language and discuss confounding
Ignoring missing data	Bias	Document and handle explicitly
Late authorship discussions	Conflict	Agree roles in writing at the start

Illustrative example

Invented for teaching. A student reviews 300 charts and records "complications" without defining it. Three weeks into the review, she realises she coded "wound infection" differently from a colleague. She must recode every chart. A one-page definition of each variable at the start would have prevented the rework.

How to catch mistakes early

Ask a colleague to read your protocol before you start, run a small pilot of the data form on five records, and review the first results against the plan. If you find an error, record what changed and why. Transparent correction is a normal part of research, whereas hiding a change after seeing the results is a threat to integrity.

Illustrative example: changing an outcome

Invented for teaching. A student planned "30-day mortality" as the primary outcome but saw no difference, so she switched to "length of stay", which showed a difference. Reporting only the second outcome would mislead readers. The honest approach is to report the pre-specified outcome as primary and present the other as exploratory.

Key takeaways

Most mistakes happen before data collection, not during analysis.
A short, clear protocol and data dictionary prevent many of them.
Ask for supervision at each stage and keep a log of decisions.

References and further reading

Hulley SB, Cummings SR, Browner WS, Grady D, Newman TB. Designing Clinical Research. 4th ed. Lippincott Williams & Wilkins; 2013. Link
EQUATOR Network: Enhancing the QUAlity and Transparency Of health Research (reporting guideline library). Link
International Committee of Medical Journal Editors (ICMJE). Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals. Link