Data collection is an important part of any statistics unit. Here, students collect data about a book using the appropriate tools (MP5) and submit the data for future use.

In a lesson later in the unit, students analyze the class data they collect here using the methods they learn in the next few lessons. A copy of the class's data should be kept. It may be convenient to set up a shared spreadsheet if students have access to internet-enabled devices.

If enough different books are not available for students to measure and weigh, some online independent bookstore websites include this information. Students may look up their favorite books and use that information.

The goal for this activity is for students to see the importance of careful data collection as well as an organizational strategy for keeping up with the data as it is collected.

Consider asking some of the following questions:

• "Do you notice any patterns in the data from the table?"
• "Is the class data organized in a way that is useful for noticing patterns?" (not likely)
• "How could we reorganize the table to make it more useful?" (sort from fewest pages to most or lightest to heaviest)
• "What questions do you have about the data?" (Are some of the measurements related to one another? Do weight and size have any relationship?)

In this activity, students choose appropriate ways to display data using data that comes from the items students measured in the previous activity (MP4).

After drawing the distributions of the individual variables and then the scatter plot, students look for patterns in the data that might not have been visible in the tabular format.

Monitor for students who use these different representations:

• Histogram
• Dot plot
• Box plot

Each can be effectively used to display numerical data from a single variable.

In the digital version of the activity, students use an applet to create visual representations of data. The applet allows students to enter data in a spreadsheet and let the computer create the visualization. Use the digital version if available to allow students to focus on selecting a good visualization without worrying about construction.

The goal of the discussion is for students to explore appropriate data representations including one of the main focuses of the unit: scatter plots.

Display 2–3 representations from previously selected students for all to see. Use Compare and Connect to help students compare, contrast, and connect the different representations (histograms with different bin sizes, box plot, dot plot, or scatter plots with axes switched). Here are some questions for discussion:

• “What do the representations have in common? How are they different?”
• (First, select a single student’s book from the data) “How does this information show up in each method?”

Make sure that students understand the distinction between representations of the distribution of a single variable (pages data alone) and this new representation that contains information about 2 variables at once (pages and weight). Tell students that we will be using scatter plots to look at the relationship between different variables that cannot be seen as easily when we represent the distributions separately.