Exploratory Data Analysis
Reference for performing EDA in service of Bayesian modeling. Read references on demand based on what the data and current step require.
Key Practices
- Confounder-aware comparisons. Any claimed association or "effect" must condition on the strongest available confounder — typically the most granular temporal unit, or the variable with the highest marginal association to both predictor and outcome. Never report unconditional means as effects. Always report sample size per arm.
Process references
Operational checklists and procedures for each step of the EDA workflow:
references/process/data-semantics-audit.md — understanding what columns mean (scientific domain, column roles, granularity, sparsity, encoding sanity, suspicious patterns)
references/process/standardization.md — mechanical cleanup driven by the audit (snake_case names, NaN harmonization, type coercion, categorical normalization) that produces the canonical cleaned dataset
references/process/data-quality-checks.md — missingness, duplicates, invalid values, type issues
references/process/timestamp-handling.md — parsing timestamps, frequency inference, gaps, panel coverage
references/process/visualization.md — plot quantity, structure, and documentation requirements
references/process/modeling-handoff.md — variance decomposition, residual analysis, competing structural hypotheses, dependence classification, likelihood mapping, modeling-ready recommendations
For the HTML report format (design, palette, fonts, skeleton template), see artifact-guidelines > references/html-report. For log format, see artifact-guidelines > references/markdown-report.
Test references
Statistical diagnostic tests organized by data shape. Load only what your data needs:
references/tests/distribution.md — normality tests (Shapiro-Wilk, Jarque-Bera, Anderson-Darling), QQ-plot patterns, formal goodness-of-fit (KS, AD)
references/tests/regression.md — heteroscedasticity (Breusch-Pagan, White, Goldfeld-Quandt), multicollinearity (VIF, condition number), specification (Ramsey RESET), influence diagnostics (leverage, Cook's D, DFBETAS, Studentized residuals, Mahalanobis)
references/tests/time-series.md — stationarity (ADF, KPSS), autocorrelation (Durbin-Watson, Ljung-Box), ACF/PACF patterns, ARCH effects
references/tests/count.md — overdispersion (Cameron-Trivedi, dispersion parameter), zero-inflation, Vuong test for non-nested models
references/tests/missing-and-hierarchical.md — MCAR/MAR/MNAR mechanisms, Little's test, ICC, design effect
Key Thresholds Summary
| Test |
Threshold |
Interpretation |
| Shapiro-Wilk W |
> 0.95 |
Approximately normal |
| VIF |
> 10 |
Severe multicollinearity |
| Durbin-Watson |
1.5-2.5 |
No serious autocorrelation |
| ADF critical |
-2.86 |
5% significance |
| Cook's D |
> 1 |
High influence |
| ICC |
> 0.05 |
Use multilevel model |
| Dispersion φ |
> 2 |
Overdispersion |
1---2name: eda3description: Exploratory data analysis reference for Bayesian modeling — operational EDA procedures (data semantics audit, quality checks, timestamp handling, visualization, modeling handoff) plus a diagnostic test library indexed by data shape.4---56# Exploratory Data Analysis78Reference for performing EDA in service of Bayesian modeling. Read references on demand based on what the data and current step require.910## Key Practices1112- **Confounder-aware comparisons.** Any claimed association or "effect" must condition on the strongest available confounder — typically the most granular temporal unit, or the variable with the highest marginal association to both predictor and outcome. Never report unconditional means as effects. Always report sample size per arm.1314## Process references1516Operational checklists and procedures for each step of the EDA workflow:1718- `references/process/data-semantics-audit.md` — understanding what columns **mean** (scientific domain, column roles, granularity, sparsity, encoding sanity, suspicious patterns)19- `references/process/standardization.md` — mechanical cleanup driven by the audit (snake_case names, NaN harmonization, type coercion, categorical normalization) that produces the canonical cleaned dataset20- `references/process/data-quality-checks.md` — missingness, duplicates, invalid values, type issues21- `references/process/timestamp-handling.md` — parsing timestamps, frequency inference, gaps, panel coverage22- `references/process/visualization.md` — plot quantity, structure, and documentation requirements23- `references/process/modeling-handoff.md` — variance decomposition, residual analysis, competing structural hypotheses, dependence classification, likelihood mapping, modeling-ready recommendations2425For the HTML report format (design, palette, fonts, skeleton template), see `artifact-guidelines > references/html-report`. For log format, see `artifact-guidelines > references/markdown-report`.2627## Test references2829Statistical diagnostic tests organized by data shape. Load only what your data needs:3031- `references/tests/distribution.md` — normality tests (Shapiro-Wilk, Jarque-Bera, Anderson-Darling), QQ-plot patterns, formal goodness-of-fit (KS, AD)32- `references/tests/regression.md` — heteroscedasticity (Breusch-Pagan, White, Goldfeld-Quandt), multicollinearity (VIF, condition number), specification (Ramsey RESET), influence diagnostics (leverage, Cook's D, DFBETAS, Studentized residuals, Mahalanobis)33- `references/tests/time-series.md` — stationarity (ADF, KPSS), autocorrelation (Durbin-Watson, Ljung-Box), ACF/PACF patterns, ARCH effects34- `references/tests/count.md` — overdispersion (Cameron-Trivedi, dispersion parameter), zero-inflation, Vuong test for non-nested models35- `references/tests/missing-and-hierarchical.md` — MCAR/MAR/MNAR mechanisms, Little's test, ICC, design effect3637## Key Thresholds Summary3839| Test | Threshold | Interpretation |40|------|-----------|----------------|41| Shapiro-Wilk W | > 0.95 | Approximately normal |42| VIF | > 10 | Severe multicollinearity |43| Durbin-Watson | 1.5-2.5 | No serious autocorrelation |44| ADF critical | -2.86 | 5% significance |45| Cook's D | > 1 | High influence |46| ICC | > 0.05 | Use multilevel model |47| Dispersion φ | > 2 | Overdispersion |