Changes in version 2026-04-05                      

Breaking Changes

  - Parameter names simplified: All parameter names have been changed to
    remove the confusing l prefix. The new naming pattern is
    {pre_state}{post_state}:
      - No-DK model: lgg → gg, lgk → gk, lkk → kk (gamma unchanged)
      - DK model: lgg → gg, lgk → gk, lgd → gd, lkg → kg, lkk → kk, lkd
        → kd, ldd → dd
      - This is a breaking change - update code that accesses parameters
        by name

New Features

  - Simulation functions: Added simulate_lca() and simulate_lca_dk() to
    generate data from known parameters for validation studies
  - Parameter recovery validation: Added validate_recovery() for Monte
    Carlo validation of parameter estimates
  - Comprehensive validation tests: New test files for parameter
    recovery, individual-level functions, and group adjustments

Example Migration

# Old code
result$params["lgk", ]
result$params[c("lgg", "lgk", "lkk"), ]

# New code
result$params["gk", ]
result$params[c("gg", "gk", "kk"), ]

Breaking Changes

  - DK model parameter names fixed: Parameter names in the Don't Know
    model now match the likelihood function:
      - Old: lgg, lgk, lgc, lkk, lcg, lck, lcc, gamma
      - New: lgg, lgk, lgd, lkg, lkk, lkd, ldd, gamma
      - This affects lca_cor() output when using DK data

Improvements

  - Named parameter access: All internal code now uses named row access
    (e.g., params["gamma", ]) instead of numeric indices, making the
    code more readable and robust to parameter reordering
  - GOF functions fixed: fit_model(), fit_dk(), and fit_nodk() now use
    formulas consistent with the likelihood function
  - lca_adj improved: Person-level adjustment function now correctly
    handles both DK and non-DK models with proper parameter names
  - Model criticism functions: cell_probs() and
    calculate_expected_values() now use correct DK model formulas

Bug Fixes

  - DK model cell probabilities: Fixed formulas in cell_probs() to match
    the likelihood function exactly
  - Expected values calculation: Fixed DK model expected values in
    calculate_expected_values()

                     Changes in version 2026-03-30                      

New Features

  - Comprehensive Econometric Correctness Test Suite: Added extensive
    validation tests covering likelihood derivation, parameter
    identification, standard error computation, and parameter recovery
    across various sample sizes and true parameter configurations

Bug Fixes

  - Chi-square GOF test: Fixed argument handling for chi-square
    goodness-of-fit test
  - Expected values formula: Corrected expected values computation in
    model fitting

Testing

  - Simulation helpers: Added helper-simulation.R with reusable
    functions for parameter recovery testing
  - Expanded test coverage: 612 tests (up from ~275 in v0.2.2), 7
    skipped (extended tests)
  - New test modules:
      - test-econometric-formula-derivation.R: Validates likelihood
        formula components
      - test-econometric-identification.R: Tests parameter
        identification conditions
      - test-econometric-likelihood.R: Verifies likelihood computation
        correctness
      - test-econometric-parameter-recovery.R: Monte Carlo parameter
        recovery validation
      - test-econometric-se-validation.R: Standard error computation
        verification

                     Changes in version 2025-12-15                      

Validation System Modernization

  - Complete migration to checkmate: Replaced all manual input
    validation with robust checkmate assertions
  - Enhanced validation utilities: Added comprehensive validation helper
    functions in utils-validation.R
  - Standardized error messages: All validation errors now use
    consistent checkmate format
  - Improved code quality: Eliminated all manual stop() calls and ::
    namespace patterns
  - Dependency optimization:
      - Added checkmate dependency for robust input validation
      - Removed goji dependency by implementing internal zero1 function
  - Test suite updates: Updated all test expectations to match new
    validation patterns
  - Documentation improvements: Enhanced validation function
    documentation with proper @importFrom declarations

Development Workflow Improvements

  - Local code coverage: Replaced Codecov.io with simple local coverage
    reporting
      - Added make coverage command for quick coverage analysis
      - Created Makefile for common development tasks
      - Removed external Codecov dependency and badge
  - Fixed CRAN URL: Updated to canonical CRAN package URL format

                     Changes in version 2024-12-15                      

Infrastructure & Modernization

  - Added comprehensive GitHub Actions CI/CD workflows for R CMD check,
    test coverage, and pkgdown
  - Updated minimum R version requirement to 4.0.0
  - Modernized code patterns:
      - Replaced T/F with TRUE/FALSE throughout
      - Updated logical operators to use || for scalar comparisons
      - Removed deprecated stringsAsFactors arguments
      - Added explicit parameters to mapply() calls
  - Enhanced package metadata in DESCRIPTION
  - Improved .gitignore and .Rbuildignore patterns
  - Re-enabled and configured lintr for code quality checks
  - Updated pkgdown configuration URLs

                       Changes in version 2017-05                       

  - Consistent support for input data format (with potential for d for
    'don't know').
  - Person level adjustments for LCA and standard correction
  - Explain logic for Rsolnp priors and allow people to pass different
    priors
  - Standard output and nomenclature for stnd_cor and lca_cor, including
    option for s.e.
  - Extensive linting, expect_lint_free passes