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Pie Chart vs Bar Graph Comparison

Run the Pie Chart vs Bar Graph Comparison MicroSim Fullscreen

About This MicroSim

Sylvia says: "Acorn for your thoughts - which chart makes the data easier to read? That's exactly what we're exploring here! This MicroSim puts a pie chart and bar graph side by side, showing the exact same data. Your job is to play detective and figure out when each chart type shines."

You can include this MicroSim on your website using the following iframe:

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<iframe src="https://dmccreary.github.io/statistics-course/sims/pie-vs-bar-comparison/main.html" height="542px" scrolling="no"></iframe>

How to Use

  1. Adjust the sliders to change the values for each category (Cat A through Cat D)
  2. Select a preset from the dropdown to see different data scenarios:
  3. Easy to compare: Values with clear differences
  4. Similar values: Nearly equal values - notice which chart makes differences easier to spot
  5. Many categories: More categories to compare (expands to 6)
  6. One dominant: One category dominates - see how each chart handles this
  7. Toggle display options:
  8. Show %: Display percentages on both charts
  9. Values: Display raw values

What to Look For

As you experiment, ask yourself these questions:

  • When values are similar, which chart makes it easier to spot small differences?
  • When one category dominates, does the pie chart or bar graph communicate this better?
  • For comparing exact values, which chart gives you more precision?
  • For understanding "part of a whole", which chart works better?

Key Insights

After exploring, you'll discover that:

  • Pie charts work well for showing proportions and "part of a whole" relationships, especially when one or two categories dominate
  • Bar graphs excel at comparing exact values, especially when differences are small
  • Similar values are notoriously hard to compare in pie charts - the wedges look almost identical!
  • Many categories become cluttered in pie charts but remain clear in bar graphs

Lesson Plan

Learning Objective

Students will be able to compare and contrast the effectiveness of pie charts versus bar graphs for different data distributions, and analyze which visualization type best supports specific data interpretation tasks.

Grade Level

High School (Grades 9-12), AP Statistics

Duration

15-20 minutes

Prerequisites

  • Understanding of categorical data
  • Familiarity with basic chart reading

Activities

Activity 1: First Impressions (5 minutes)

  1. Load the MicroSim with default values
  2. Have students write down which chart feels easier to read and why
  3. Discuss: What makes one chart "easier" than another?

Activity 2: Preset Exploration (5 minutes)

  1. Have students try each preset in order
  2. For each preset, ask: "Which chart communicates the data more effectively?"
  3. Students record observations in a table:
Preset Better Chart Why?
Easy to compare
Similar values
Many categories
One dominant

Activity 3: Create Your Own Scenario (5 minutes)

  1. Challenge students to create slider values that make the pie chart clearly better
  2. Then create values that make the bar graph clearly better
  3. Share discoveries with a partner

Activity 4: Real-World Application (5 minutes)

Discuss: Given what you've learned, which chart would you use for:

  • Showing how a household budget is divided among categories?
  • Comparing test scores across five classes?
  • Showing market share of the top two companies?
  • Displaying survey results with many response options?

Assessment Questions

  1. A survey shows that 47% of students prefer pizza, 44% prefer tacos, and 9% prefer salad. Which chart would better show the close race between pizza and tacos? Explain your reasoning.

  2. Your data has 8 categories with values ranging from 5% to 18%. Explain why a bar graph would be more appropriate than a pie chart.

  3. Create a scenario where a pie chart would be the better choice. Describe the data and explain your reasoning.

Extension Activities

  • Have students find real-world examples of pie charts and bar graphs and critique whether the appropriate chart type was used
  • Create guidelines for when to use each chart type
  • Explore what happens with negative values (which only bar graphs can show)

References