Reproducibility materials for the manuscript “Coding is Construction, Contrast is Extraction: Disentangling the Terminological Knot in R Linear Models” by Giulio Vidotto and Umberto Granziol, submitted to Behavior Research Methods. The repository contains the R code needed to reproduce the simulated examples, coding matrices, augmented design bases, inverse hypothesis matrices, interaction demonstrations, and planned-contrast computations reported in the manuscript. No empirical dataset is associated with the manuscript. All numerical examples are simulated or generated algebraically by the accompanying R code.