Deadlines
- Moodle Reading Mon Sep 27, midnight
- Practice 3 Mon Sep 27, midnight
- Book Ch. 2 — How a Number Comes to Be — read for Forum 2, Fri Oct 1 (next week)
- Quiz 2 Fri Sep 24, in class
Week 4: Relational Tables — keys, joining and tidying
Learning Objectives
- 04A I can describe the structure of relational data and identify key columns and relationships between tables.
- 04B I can join tables using different join types (inner, left, right, outer) and explain when each is appropriate.
- 04C I can reshape data between wide and long (tidy) formats.
Perspectival Reading
Reading: TBD
Reflection Questions
- The relational model assumes data can be cleanly separated into tables with keys. What kinds of knowledge resist this structure?
- When tables from different sources are joined, whose data definitions take precedence?
- Tidy data is a design choice — what does it mean to say data is “messy”?