Research guide

Preregistration and analysis plans: decisions before results

Preregister questions, outcomes, sampling and confirmatory analyses; disclose prior data access, changes and exploratory work with a transparent decision record.

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Prepared by: Dr. Didgar Research Institute · Last revised: · 3 min read
Expected deliverables
  • Prepare an assessable plan, prior-access disclosure and deviation log.
Decision workbook and example

Why record decisions in advance?

Preregistration makes planned decisions distinguishable from choices informed by results. It supports transparency rather than certifying study quality. Exploratory work remains valuable when it is clearly identified instead of presented as a prespecified confirmation.

Specify actionable details

Include questions, hypotheses, primary outcomes, measurement, population, sampling, sample-size justification, stopping rules, exclusions, missing-data handling and the main model. Explain multiple-testing decisions when appropriate. Saying that a suitable test will be selected leaves the critical choice undocumented.

Be candid about existing data

For secondary data or a late registration, record which information and outcomes were already known and when they were accessed. Do not change the original date or describe a plan made after inspecting outcomes as the initial plan.

Changes and registry selection

A design problem or a better method may justify a change. Preserve the original version, date, rationale and implications; label additional analyses. Choose a registry appropriate to the discipline and institutional requirements, and check its current service conditions. Review protocols and trial registrations have different purposes.

Prepare an auditable package

Deliver the readable analysis plan, registration identifier, amendments and a planned-versus-executed table. Adapt the downloadable toolkit template to the study. Preregistration does not replace ethics review, consent or other mandatory study registration.

Practical research checklist

  • Define primary outcomes and models in advance.
  • Disclose prior access to data.
  • Retain dated and justified amendments.
  • Label exploratory analyses clearly.

Worked case and implementation decisions

The following is a fictional teaching case. Do not use its numbers or wording as actual study findings.

The teaching plan identifies score as the primary outcome, one semester as the window and a defined planned model. A later-discovered variable is exploratory and described in a dated amendment, not silently inserted into the old plan. New, secondary and qualitative data need different registration choices. Registered Reports are not equivalent to uploading a form. Specify decisions sufficiently to distinguish prospective commitments from choices made after viewing data.

Worked case and implementation decisions
StageTeaching exampleVerification question
QuestionDefined association, not desired resultAre hypothesis and units clear?
Prior accessWhich data/outputs were seen?Is this disclosed before registration?
PlanOutcome, exclusions, missingness and modelAre ambiguous choices reduced?
AmendmentChange after a new variable is seenAre date, reason and consequence recorded?
ReportPlanned and exploratory separatedDoes it match registration history?

Exercise output: Prepare an assessable plan, prior-access disclosure and deviation log.

Sources and further reading

Official sources for verification and further reading

This guide supports research learning and planning; align implementation with the actual design and institutional requirements. Editorial policy
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