# Experimental Plan Template (Pre-Registration Style)

## 1. Study Information

**Title:** [Descriptive title]

**Authors:** [Names]

**Date:** [Pre-registration date]

**Version:** [1.0]

## 2. Research Questions & Hypotheses

**Primary research question:** [What is the main question this study answers?]

**Hypotheses:**

- H₀ (null): [Statement of no effect]
- H₁ (alternative): [Statement of expected effect]

**Secondary questions:** [1-3 additional questions, if any]

**Exploratory questions:** [Questions without directional predictions]

## 3. Design

**Design type:** [ ] Randomized experiment [ ] Quasi-experiment [ ] Observational study [ ] Other: ______

**Design specification:** [ ] CRD [ ] RCBD [ ] Factorial [ ] Crossover [ ] Longitudinal [ ] Case-control [ ] Cohort

**Randomization unit:** [ ] Individual [ ] Cluster [ ] Block [ ] Other: ______

**Analysis unit:** [Same as randomization unit, or specify if different]

**Blinding:** [ ] None [ ] Single-blind [ ] Double-blind

## 4. Sample Size / Power

**Power analysis parameters:**

| Parameter | Value | Source |
|-----------|-------|--------|
| α (Type I error) | 0.05 | Convention |
| Power (1 − β) | 0.80 | Convention |
| Expected effect size | [value and metric] | [prior study, pilot, or MDE] |
| Minimum detectable effect | [value] | [computed] |
| Required sample size (total) | [N] | [computed] |
| Attrition adjustment | [additional N] | [expected dropout rate] |
| **Final target N** | **[N]** | |

**Power analysis output:** [Attach or reference the power analysis script output]

## 5. Participants / Subjects

**Target population:** [Who/what are we studying?]

**Inclusion criteria:**

1. [Criterion 1]
2. [Criterion 2]

**Exclusion criteria:**

1. [Criterion 1]
2. [Criterion 2]

**Recruitment:** [How will participants be identified and recruited?]

**Assignment:** [How will participants be assigned to conditions?]

## 6. Variables

### Primary Outcome

| Variable | Definition | Measurement | Type |
|----------|------------|-------------|------|
| [name] | [operational definition] | [instrument, units] | [continuous/binary/time-to-event] |

### Secondary Outcomes

| Variable | Definition | Measurement | Type |
|----------|------------|-------------|------|
| [name] | | | |

### Predictors / Treatments

| Variable | Levels | Assignment | Notes |
|----------|--------|------------|-------|
| [name] | [level1, level2, ...] | [randomized/observed] | |

### Covariates (pre-registered)

| Variable | Rationale |
|----------|-----------|
| [name] | [why this variable is included] |

## 7. Procedure

**Timeline:**

| Phase | Activity | Duration |
|-------|----------|----------|
| 1 | Recruitment | [time] |
| 2 | Pre-treatment measurement | [time] |
| 3 | Treatment administration | [time] |
| 4 | Post-treatment measurement | [time] |
| 5 | Follow-up | [time] |

**Detailed protocol:** [Step-by-step description of what happens to each participant]

## 8. Analysis Plan

### Primary Analysis

**Method:** [e.g., Independent t-test, linear regression, ANCOVA]

**Model specification:** [e.g., outcome ~ treatment + covariate1]

**Assumptions to be checked:**

| Assumption | Diagnostic | Remediation If Violated |
|------------|------------|------------------------|
| Normality | Shapiro-Wilk, Q-Q plot | Transform data or use nonparametric test |
| Equal variance | Levene's test | Welch's correction |
| Independence | Durbin-Watson | GLS / mixed model |
| [other] | [method] | [alternative] |

### Secondary Analyses

[Method for each secondary question]

### Exploratory Analyses

[Methods for exploratory questions]

### Subgroup Analyses (pre-specified)

| Subgroup | Rationale |
|----------|-----------|
| [group] | [why this subgroup might differ] |

### Missing Data Handling

**Expected missingness:** [Amount and pattern expected]

**Primary approach:** [ ] Complete case analysis [ ] Multiple imputation [ ] Maximum likelihood [ ] Last observation carried forward [ ] Other: ______

### Multiple Testing

**Correction method:** [ ] Bonferroni [ ] Holm [ ] Benjamini-Hochberg [ ] None (confirmatory study with single primary outcome) [ ] Other: ______

**Number of comparisons:** [ ]

## 9. Data Collection & Management

**Data collection tools:** [ ] Survey platform [ ] Lab equipment [ ] Administrative records [ ] Other: ______

**Data storage:** [How and where will data be stored?]

**Quality control:** [Checks for data quality during collection]

## 10. Ethics & Reporting

**Ethics approval:** [ ] Obtained (IRB #: ______) [ ] Pending [ ] Not required

**Consent:** [ ] Written [ ] Verbal [ ] Waived

**Conflicts of interest:** [None / describe]

**Data availability:** [Where will data and code be posted?]

## 11. Changes from Original Plan

[If this is an update to a pre-registration, document any changes here with date and rationale]