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Data and Society 9-12 / Week 08 / Wednesday
3/6
Week 08 · Charts That Mislead

Wednesday

Count Lab: Redraw it honestly
// How a true number can tell a false story
⏱ about 20 min

Wednesday: Count Lab: Redraw It Honestly

Comet finds a second poster in her bag. It shows the Q1 answers, with the y-axis starting at 8.

"I made this one the same night," she admits. "Same trick, I guess."

Wren lays both posters side by side. "What do you notice? Both make the smallest bar almost vanish."

Nova hovers over the workbench and projects an empty grid. "Would you like a hint?" she asks.

"Write down the steps in each bar before you redraw. Then you can compare before and after."

Comet sharpens two pencils and hands you one. "Let's rebuild them, honest this time."

Your mission

You will redraw Comet's two posters with a y-axis from 0, equal steps, a title and a source line.

Then you will compare how the bars looked before and after.

  • Graph paper, or lined paper and a ruler
  • A pencil and an eraser
  • The two tables below
Q3 answerMembersSteps on poster 1 (axis from 4)
Longer evening hours139
Quiet study room117
Repair bench95
Bike rack51
Q1: How often do you visit?MembersSteps on poster 2 (axis from 8)
Less than once a week91
1 or 2 times a week179
3 or more times a week146

Made-up data from the Commons Count story. Q1 adds up to 40, all who answered.

PREDICT BEFORE YOU REDRAW
  • Read the question.
  • Tap your answer.
On poster 2, how many times as tall does the 17 bar look next to the 9 bar?
In the real numbers, how does 17 compare with 9?
On your honest redraw of poster 2, how many steps tall is the 14 bar?
  1. Draw an x-axis and a y-axis for poster 1.
  2. Number the y-axis from 0 to 14 in equal steps of 1.
  3. Draw the four Q3 bars to their full numbers.
  4. Add a title and the source line: Commons Count survey, made-up data.
  5. Draw a second x-axis and y-axis for poster 2.
  6. Number this y-axis from 0 to 18 in equal steps of 1.
  7. Draw the three Q1 bars to their full numbers.
  8. Add a title and the same source line.
  9. Under each graph, copy the before and after table and fill in the after column.
PosterTallest bar compared with shortest, beforeTallest bar compared with shortest, after
Poster 1 (Q3)9 steps to 1 step13 steps to 5 steps
Poster 2 (Q1)9 steps to 1 step17 steps to 9 steps
On your graph paper, redraw both posters with y-axes from 0, equal steps, titles and source lines.
Lab checkTrue or false?
After the redraw, the bike rack bar is 5 steps tall.?
After the redraw, the tallest Q1 bar looks 9 times as tall as the shortest.?
The numbers in the tables changed when we redrew the posters.?
Both honest redraws start the y-axis at 0.?
WHY THIS EXERCISEAn honest redraw changes how the data look, never what the data say.
On the honest Q3 graph, longer evening hours is 13 steps and bike rack is ____ steps.
Twice 9 is ____, so 17 is a little less than 2 times 9. Type the number as a word.

Excellent lab work, data analyst. Tomorrow you will check whether a chart really supports the claim beside it.

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