Source-reviewed knowledge center

Practical guidance with explicit provenance and source links.

Each guide shows who prepared it, its current review status, sources, publication date, last-reviewed date, and correction history. Expert review is not claimed until a named reviewer has approved the text.

Before calculating sample size, define the estimand

A sample-size formula cannot rescue an ambiguous population, outcome, contrast, time point, or handling of intercurrent events.

  • Write the population, treatment or exposure conditions, outcome, time point, and population-level contrast before choosing inputs.
  • Distinguish a detectable effect from the smallest clinically meaningful effect.
  • Record the source and uncertainty for every event rate, variance, correlation, loss-to-follow-up, and design-effect assumption.
  • Plan sensitivity scenarios rather than presenting one number as certain.
Correction history

Version 1.0 · 24 July 2026 · Initial publication. No corrections recorded.

Five statistical claims a p-value cannot support

Statistical significance alone does not establish clinical importance, causality, absence of bias, model validity, or replicability.

  • A small p-value does not measure the size or importance of an effect.
  • A non-significant result is not proof that two conditions are equivalent.
  • Association does not become causal because confounders were entered into a model.
  • Model output is not reliable until assumptions, missingness, multiplicity, and data quality are addressed.
Correction history

Version 1.0 · 24 July 2026 · Initial publication. No corrections recorded.

What a resident should be able to teach back before defense

A defensible project requires the researcher to explain why the design and analysis answer the question—and where they do not.

  • State the research gap, primary objective, and primary outcome in plain language.
  • Explain the sampling pathway and the most important selection-bias risk.
  • Interpret effect estimates and confidence intervals before discussing p-values.
  • Name limitations, their likely direction, and the claims that should therefore be avoided.
Correction history

Version 1.0 · 24 July 2026 · Initial publication. No corrections recorded.

De-identification is a risk review, not a single delete command

Removing names is necessary but may not be sufficient when dates, rare conditions, geography, free text, or linked variables can identify a person.

  • Start with authority, purpose, recipients, environment, and minimum necessary fields.
  • Separate direct identifiers and linkage keys from the analytical working copy.
  • Review combinations of indirect identifiers and small cells.
  • Record residual risk, access rules, retention, and the person who approved release.
Correction history

Version 1.0 · 24 July 2026 · Initial publication. No corrections recorded.

Responsible AI disclosure needs purpose, location, and verification

Naming a tool is not enough. Authors should document what it did, where its output appears, and how humans verified accuracy and originality.

  • Do not list an AI system as an author.
  • Do not upload confidential manuscripts or identifiable data where confidentiality is not assured.
  • Verify factual claims, calculations, citations, images, and wording against authoritative sources.
  • Follow the target journal and institution even when their required disclosure is stricter.
Correction history

Version 1.0 · 24 July 2026 · Initial publication. No corrections recorded.

Corrections

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