Participant studies
Plan a powered participant study
Use measurement packs, a transparent sample-size approximation, a pre-launch audit, and a machine-readable variable codebook.
The basic idea
Convenient defaults should reduce setup work without pretending to replace research design. Start with an editable measurement pack, identify one primary outcome, plan recruitment from an explicit effect and attrition assumption, and preserve the final variable coding with the study.
Add the persuasion and correction pack to a council-versus-solo study, plan for a standardized mean difference of 0.30 with 80 percent power and 15 percent attrition, then resolve every blocking readiness item before opening recruitment.
How to do it
- 1
Choose a measurement pack that matches the construct, then edit every item so it fits the actual stimulus and population.
- 2
Enter the smallest effect worth detecting, target power, and expected attrition; use the resulting recruitment total as a planning cap when its assumptions fit.
- 3
Resolve blocking readiness items and review recommended pre/post, attention, and treatment-exposure checks.
- 4
Save the draft and download the CSV or JSON variable codebook alongside the protocol and eventual response data.
What to watch for
- The quick power planner is a normal-approximation for equal-size independent groups, not a substitute for clustered, longitudinal, binary, or multiplicity-aware power analysis.
- Adding a pack does not validate a scale or make its items appropriate for a new population.
- A forecasting probability becomes objectively scorable only after the event outcome and scoring rule are prespecified.
What a useful result looks like
The study begins recruitment with an explicit outcome hierarchy, documented measurement coding, visible design warnings, and a defensible first-pass recruitment target.