qdaR 0.1.0

First release.

• Reads all nine formats of the zotQDA exchange contract v1, validating the format stamp, the version and the promised columns; refuses an export from a newer version rather than guessing at it. Reference files are installed with the package, so every example, test and vignette chunk runs without a Zotero installation and without network access.
• Projects from other QDA software can be read through the REFI-QDA interchange standard (qda_read_qdpx()); the subset a .qdpx file supports is reported on import.
• Reproduces the plugins’ graphics with ggplot2 – code frequencies, the code-document matrix, saturation, timeline, MDS – and can additionally re-render the original Vega-Lite chart specifications unchanged via the suggested vegawidget package.
• Intercoder reliability reimplemented independently of the plugins: percentage agreement, Cohen’s and Fleiss’ kappa, Brennan and Prediger’s coefficient, Krippendorff’s alpha and Gwet’s AC1, each with bootstrap or Wilson confidence intervals, plus level-wise agreement over a hierarchical code system, the confusion table and the annotation paradox diagnostics. Checked against frozen results of the plugins’ JavaScript implementation.
• The reliability of the segmentation itself, before categories are even compared: Krippendorff’s unitizing alpha, Mathet’s gamma with its best alignment, WindowDiff and Pk.
• Progress and reporting: saturation measures with a stopping criterion, code drift across coding sessions, and generated COREQ and SRQR checklists.
• Inferential statistics the plugins deliberately leave out: chi-squared tests of code-by-group tables with Cramér’s V and an exact or Monte Carlo fallback, Jaccard code distances, classical multidimensional scaling, hierarchical clustering with the cophenetic correlation, and correspondence analysis with the share of inertia shown.
• Licensed AGPL-3 with one additional permission on top: what you produce with the package – results, figures, reports – is yours, unconditionally.