# Choosing a research design: questions, data and methods

Decision workbook and teaching example · 2026-10-06

The completed case is fictional. Its values and decisions are not actual findings; complete your project using relevant permissions, methods and requirements.

- Project: ____________________
- Researcher and role: ____________________
- Date and version: ____________________
- Data seen before the decision: ____________________
- Aim and scope: ____________________

## Completed example

| Stage/decision | Example | Check or action |
| --- | --- | --- |
| Question | Description, association or effect? | Is the claim type explicit? |
| Time | Before and after exposure | Is temporal order known? |
| Selection | Volunteers or probability sample | Is selection bias assessed? |
| Measurement | Comparable definitions across groups | Is comparison valid? |
| Integration | Defined quantitative and qualitative roles | How do outputs answer one question? |

## Complete your own record

| Topic | Actual decision and reason | Evidence link and status |
| --- | --- | --- |
| Question | __________ | __________ |
| Time | __________ | __________ |
| Selection | __________ | __________ |
| Measurement | __________ | __________ |
| Integration | __________ | __________ |

## Completion checks

- [ ] Create a design rationale and claim/data/assumption matrix.

## Changes and limitations

| Date | Change | Data known at decision time | Reason | Consequence for claim | Reviewer |
| --- | --- | --- | --- | --- | --- |
| __________ | __________ | __________ | __________ | __________ | __________ |

## Sources and further reading

- [CASP — Critical appraisal checklists](https://casp-uk.net/casp-tools-checklists/)
- [EQUATOR Network — Reporting guidelines](https://www.equator-network.org/)
- [Hernán & Robins — Causal Inference: What If (author-hosted book, 2024 version)](https://www.hsph.harvard.edu/miguel-hernan/wp-content/uploads/sites/1268/2024/04/hernanrobins_WhatIf_26apr24.pdf)

Related guide: https://didgar-research-site1.vercel.app/en/guides/research-design/