Reading a Dot Plot (Group A)
The dot plot below is a name length data visualization created by a group of 25 students (Group A).
1 What is the difference (in letters) between the longest and shortest name?
2 What is the most common name length?
3 What fraction of students have first names that are 5 letters long?
Interpreting Peaks, Clusters, Gaps, and Outliers
4 The distribution of the data is the way that it is spread out on the number line. One way to describe distribution is by identifying peaks, clusters, gaps, and outliers. As a class, label any peaks, clusters, gaps, or outliers on the dot plot above.
5 Let’s think about what those peaks, clusters, gaps and outliers tell us about the dataset. In the dot plot above:
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the peak indicates that letters is the most common name length
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the cluster indicates that many students' names are letters
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the gaps tell us that, in this sample, no students have names that are letters or letters
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the outlier is letters, telling us that longer names are uncommon in this sample.
Reading a Dot Plot (Group B)
6 Label the peaks, clusters, gaps, and outliers of this new dot plot representing the name lengths of a different group of 25 students (Group B).
7 What do the peaks, clusters, gaps, and outliers tell you about the dataset?
Typicality of Name Length Data
8 What do you think is a typical value in Group A? (There is more than one correct response.) Explain your reasoning.
9 Identify another value someone else might claim is typical of Group A. Why would they choose that value?
10 Would 6 letters be a good description of the typical number of letters in students' names for Group B? Explain.
These materials were developed partly through support of the National Science Foundation, (awards 1042210, 1535276, 1648684, 1738598, 2031479, and 1501927). 
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