Lesson Plan

Distinguish between categorical and measurement (numerical) data and explain why scatter plots are not appropriate for categorical variables

Construct a two-way frequency table from raw data on two categorical variables, correctly placing joint frequencies in cells, marginal frequencies in row and column totals, and the grand total in the corner

Calculate relative frequencies from a two-way table in three ways: relative to the grand total, relative to row totals, and relative to column totals

Use row or column relative frequencies to determine whether two categorical variables show evidence of association, by comparing the conditional distributions across categories

Interpret patterns of association in context and explain informally why association does not imply causation

8.SP.A.4

8.SP.A.4: Understand that patterns of association can also be seen in bivariate categorical data by displaying frequencies and relative frequencies in a two-way table. Construct and interpret a two-way table summarizing data on two categorical variables collected from the same subjects. Use relative frequencies calculated for rows or columns to describe possible association between the two variables. For example, collect data from students in your class on whether or not they have a curfew on school nights and whether or not they have assigned chores at home. Is there evidence that those who have a curfew also tend to have chores?