Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can explain what a cell, a row total, a column total and the grand total of a two-way table each count. (Guide: “Two-way tables”)
- I can explain why counts can mislead when groups have different sizes, and why proportions within each group are fair. (Guide: Worked example 1; Practice Q6)
- I can say what the width, the height and the area of a rectangle in a mosaic plot each show. (Guide: “Mosaic plots”; Practice Q3, Q7)
- I can explain what it means for two categorical variables to be associated, and what no association looks like on a graph. (Guide: “Association between two categorical variables”; Practice Q2)
Skills
- I can complete a two-way table with missing cells and totals, and check it against the grand total. (Practice Q4, Q6)
- I can find the distribution of one variable within each category of the other. (Guide: “Two-way tables”; Practice Q5)
- I can draw a segmented bar chart with bars of height 1, segments in the same order and a key that does not rely on colour. (Guide: “Segmented bar charts”; Practice Q5)
- I can choose the right graph for a comparison and describe a fair side-by-side bar chart. (Practice Q1, Q6)
- I can recover counts from a mosaic plot using width × height × total. (Guide: Worked example 2; Practice Q3, Q7)
Reasoning
- I can decide whether two categorical variables appear to be associated and justify it with within-group proportions. (Practice Q4, Q7)
- I can support or reject a claim in context, quoting the proportions it depends on. (Guide: Worked example 1; Practice Q5, Q6)
- I can explain why an association in observational data does not show cause and effect. (Guide: “Association between two categorical variables”; Practice Q6)
All ticked? Move on to the Topic 2.2 study guide, Summary Statistics for Two Categorical Variables, or return to the course roadmap.