Plotting Data

5 min

Teacher Prep
Setup
2 minutes of quiet work time followed by a whole-class discussion.

Narrative

The purpose of this Warm-up is for students to recall ways that two different sets of data can be represented. Data visualization is very useful for understanding patterns that are not visible in other ways. Different representations can highlight different aspects of the data and lead the viewer to see different patterns (MP7).

Students are given two scenarios and asked for appropriate representations. One scenario contains quantitative data (distance run) while the other has categorical data (favorite color). Each scenario can be represented in more than one way. As students work, monitor for different students using a variety of display choices.

Launch

Give students 2 minutes of quiet work time followed by a whole-class discussion. 

Ask students to brainstorm different graphical displays of data they have used or seen in the past. Record and display answers for all to see.

Student Task

Lin surveyed 30 students about the longest time they had ever run.

Andre asked them about their favorite color.

How could Lin and Andre display their data sets? Would they represent them in the same way? Why or why not?

Sample Response

Sample response: For the longest run, Lin could use a dot plot, a histogram, or a box plot. For the colors, Andre can use a bar graph or a circle graph. They represent the data in different ways because Lin's data is numerical and Andre's is categorical.

Activity Synthesis (Teacher Notes)

The purpose of the discussion is for students to think about different representations of data and to emphasize the difference in categorical and numerical data types.

Select previously identified students to share their responses and record for all to see. To highlight the differences between the representations, ask:

  • "What patterns would Lin be able to see if she represented her data with a dot plot? With a histogram? With a box plot?" (A dot plot would show all of the data, so would be good for showing details. A histogram would give a good overall picture of the data, but would hide details. A box plot would also be useful for showing an overview of the data and would highlight the median, but would not show the individual data values.)
  • "What patterns would Andre be able to see if he represented his data with a bar graph? With a circle graph?" (A bar graph would be useful for quickly seeing the relative order of color preferences. A circle graph would be useful for quickly seeing how preferred each color is when compared to the whole.)

After the responses have been shared, ask, "Why couldn't Lin and Andre use the same graph type to represent their data?" (Lin has numerical data and Andre has categorical data.)

Standards
Building On
  • 6.SP.4·Display numerical data in plots on a number line, including dot plots, histograms, and box plots.
  • 6.SP.B.4·Display numerical data in plots on a number line, including dot plots, histograms, and box plots.

10 min

20 min