Lesson 2.9b: Patterns in Group Comparisons
Lesson
Introduction - Find Meaning in Patterns These lessons review some patterns that are often found in graphs, what the patterns may mean, and how we can help students describe and talk about the patterns in more detail. We will explore the following patterns that often show up in different kinds of analyses: Lesson 2.9a: Patterns along one axis, Lesson 2.9b: Patterns in group comparisons, Lesson 2.9c: Patterns in XY space, and Lesson 2.9d: Patterns in change through time In this lesson, we will review Patterns in Group Comparisons. When students compare two or more distributions, the relative positions of the distributions along the same scale provide clues to deciding whether the groups are the same, similar, or different. Key concepts for students: Identifying the relative positions of groups along an axis helps you compare the range/spread of the different groups; Comparing the relative positions of each group's center(s) helps you see how the different measures of center vary or not between the groups; Exploring how spread out the distributions of each group are helps you determine if one group is more variable than the other; Comparing if the distribution shapes of each group are the same or different helps you determine if the overall shapes overlap or differ greatly. This section summarizes patterns when comparing groups using distribution graphs (dot plots, box plots, or histograms) that are described in more detail in Lesson 2.3. Key Words: Distribution, Interquartile Range
Topics and standards: Comparing Groups