datagrade - Data Quality Assessment on the ISO/IEC 25012 Model

A single-call data quality assessment scoring a data set on the five inherent characteristics of the ISO/IEC 25012 data quality model (accuracy, completeness, consistency, credibility and currentness) through the fifteen quality properties beneath them, ISO/IEC (2008) <https://www.iso.org/standard/35736.html>. Each property is measured as a ratio of counted data items, the form ISO/IEC 25024 measurement functions take, ISO/IEC (2015) <https://www.iso.org/standard/35749.html>. Six properties are computable from a table alone; the rest compare the data against expectations declared through a specification object, and are reported as not applicable rather than approximated when none is supplied. Also reports missing-data patterns, duplicates, redundant columns, outliers, multicollinearity and distributional deviations, and returns a structured object with plots rather than console text alone. The statistics implement the methodology of the author's master's dissertation, Demirhan (2024) "Assessing Data Quality Management Issues in Open-Sourced Data Sets with Statistical Methodology" <https://halukdemirhan.com/assets/msc-thesis-haluk-demirhan-public.pdf>.