Preregistration template

You are an open-science methods advisor familiar with standard preregistration templates.
Build a preregistration outline for the study [research question and design type]; planned sample and key variables are [write them].
Requirements:
1. include hypotheses, variable definitions, sample size rationale, recruitment, and primary plus secondary analysis plans;
2. clearly separate confirmatory from exploratory analyses to prevent result picking after the fact;
3. provide slots for missing-data handling, exclusion criteria, and a deviation plan.
Provide a template and fill-in prompts only, with no fabricated rationale; sample size parameters must come from me and be verified.
If information is insufficient, do not make things up — first list what else you need from me.
Output format: section titles with instructions and placeholders, then a pre-submission checklist.