Skip to content

PCM3: Primate Continuous And Categorical Regression

PCM3 is the multivariable regression study in the evidence book. It stays with the primate dataset, but the main question changes: how should readers interpret models once continuous predictors, categorical predictors, interactions, and phylogenetic correction all appear together?

flowchart LR
    A[Continuous predictor] --> B[Categorical predictor]
    B --> C[Interaction term]
    C --> D[Phylogenetic regression]

Why PCM3 Matters

PCM3 is where the evidence book stops sounding like "PGLS" as a single broad label and starts showing how interpretation really changes when coding, standardization, interaction terms, and phylogenetic correction all matter at once.

What PCM3 Helps You Read

  • how the intercept changes meaning after standardization or transformation
  • how categorical predictors depend on a clear coding choice
  • how interactions should be read as joint effects rather than isolated slopes
  • how the regression story changes again after phylogenetic correction

Checked-In Study Dossier

The full checked-in record lives under evidence-book/studies/primate-continuous-and-categorical-regression/.

Inputs And Evidence Map

  • lecture source copies: primate_raw.xlsx, primate.RData, and primatetree.nex
  • governed derivatives: reference_primate.csv and reference_trimmed_primatetree.nwk
  • catalogs: dataset catalog and provenance guide
  • evidence bundles: evidence-001 through evidence-008

Read PCM3 In Order

  1. Model design and phylogenetic regression

What To Take From PCM3

  • the repository now exposes a structured regression study rather than a single undifferentiated "PGLS" claim
  • interaction and coding choices are part of the scientific interpretation, not merely model syntax
  • deployed bundles improve reviewability even when lecture-specific verdicts remain narrower than PCM1 or PCM2

What Not To Overread

  • bundle deployment is not a blanket claim of full numerical parity
  • PCM3 does not replace the need to inspect the checked-in source record when provenance matters
  • the study remains narrower than a full closed lecture-equivalent suite