Changelog

This page is aimed at instructors reusing this book across semesters, not at students working through it. It tracks substantive changes between releases – things that could affect how you teach from a specific edition, such as corrected statistical explanations, renamed variables/datasets that assignments might reference, or reworked sections – rather than every typo fix or copyedit. If you’re a student: nothing here is required reading, and most of it is more historical trivia than anything else.

Occasional in-text footnotes flag specific corrections where it’s pedagogically useful for a reader to know something changed (e.g. a common mistake worth calling out). This page is the fuller, instructor-facing record; it isn’t meant to duplicate those footnotes, only to complement them.

0.7 (in progress)

Deliberately non-conservative revision, in progress. Notable changes so far:

  • The author is now referred to throughout as Danielle, with downstream impact on the parenthood dataset, which now has columns danielle_sleep/danielle_grump.
  • Variable and column names across the book’s code and datasets have been standardized to snake_case (previously a mix of dotted.case and camelCase). If you have assignments or slides referencing old variable/column names from 0.6.2 or earlier, they will need updating.
  • The R/RStudio/Positron installation instructions (Chapter 3) have been rewritten to reflect the current installation experience, replacing dated version numbers and screenshots-in-prose with version-agnostic guidance; Positron is now presented as an equally-weighted IDE option alongside RStudio.
  • A handful of genuine content/statistical slips inherited from the original book were corrected: an \(R^2\)-vs-adjusted-\(R^2\) mislabelling in Chapter 15, a sum-of-squares value confused with a residual sum of squares in Chapter 16, and a stray reference to nonexistent my.sleep/my.grump variables in Chapter 15’s regression walkthrough (should have read the parenthood dataset’s actual column names).
  • Several stale “future version of this book will…” asides were reworded as plain statements of scope, since no future version currently plans to add the features they described.
  • A full-book copyedit pass fixed typos, grammar, and other prose-level issues throughout.

0.6.2 (2026-07-12)

First Quarto edition. A conservative “patch” release, continuing the version lineage of the original LaTeX book (v0.6) and an unofficial, incomplete, but fabulous bookdown port (v0.6.1) courtesy of Emily Kothe, rather than starting over as v1.0. 0.6.2 itself never went live as its own public release – work moved straight from it to 0.7 before it was ever published at the book’s live URL, so no instructor ever actually taught from it. It’s included here purely to document how this Quarto book came to exist: a deliberately faithful port of the original content – known errors were logged rather than fixed – with changes limited to what was needed to make the book self-contained and executable:

  • All R code and figures are now live-executed at render time (via Quarto/knitr), rather than hand-typed output or pre-rendered images.
  • Mechanical fixes needed to make old code run under current R/package versions, and to make the book render at all (broken cross-references, outright transcription errors).
  • Custom domain, cover image, and social-card metadata added.

Previous releases

Alas, lost to the mists of time.