# User guide The user guide follows the lifecycle of a statistical analysis. Method-specific likelihood details live in the LMM, GLMM, and MMRM guides; every Python symbol is also indexed in the [API reference](../api/index.md). ::::{grid} 1 2 2 2 :gutter: 3 :::{grid-item-card} Data and formulas :link: data-and-formulas :link-type: doc Supported inputs, missingness contracts, source-row audits, formula grammar, factor handling, and design-matrix inspection. ::: :::{grid-item-card} Families and links :link: families-and-links :link-type: doc Probability calculations, default links, wrappers, censoring/survival objects, and the boundary between the family catalog and fit support. ::: :::{grid-item-card} Covariance and random effects :link: covariance-and-random-effects :link-type: doc Random blocks, structured residual covariance, visit ordering, parameterization, validation, singularity checks, and simulation. ::: :::{grid-item-card} Fitting and convergence :link: fitting-and-convergence :link-type: doc Engine and method choice, compilation, numerical controls, structured convergence, warning codes, and recovery workflow. ::: :::{grid-item-card} Inference and comparison :link: inference-and-comparison :link-type: doc Coefficient covariance, linear inference, bootstrap, result comparison, scale, and degrees-of-freedom labels. ::: :::{grid-item-card} Diagnostics and simulation :link: diagnostics-simulation :link-type: doc Auditable residual tables, random effects, singularity, reproducible simulation, and visual predictive checks. ::: :::{grid-item-card} Results and provenance :link: results-provenance :link-type: doc `FitResult`, manifests, hashes, portable archives, reports, traceability, and validation bundles. ::: :::: ```{toctree} :maxdepth: 1 data-and-formulas families-and-links covariance-and-random-effects fitting-and-convergence inference-and-comparison diagnostics-simulation results-provenance ```