Tales by Dots and Lines · Lesson 11 of 13
Infographics and Time-Use Strips
“Decode a comparison index and represent a complete day with half-hour cells.”
• Interpret a colour scale using its actual definition. • Distinguish a consumption difference index from a percentage of people. • Convert half-hour cells into durations and daily shares. • Construct and compare complete daily activity strips.
Data can be communicated through a coloured map, a band of boxes, or a familiar picture. These displays can be inviting, but they need the same careful reading as a conventional graph. A colour is meaningful only because a legend connects it to a value or category.
Here we examine a rice–wheat infographic and strips representing a day. In the first, colour encodes a comparison. In the second, colour identifies an activity and length represents time. Reading the encoding correctly is the first step in understanding either story.
Infographics
The chapter’s rice–wheat map uses a scale from −100 to +100 to show a mapped difference in per-person consumption. Negative values favour wheat, positive values favour rice, and values near zero indicate a more balanced comparison. This index is not a direct percentage of people who eat one food.
The displayed map uses historical consumption data from 2011–12. Its labels and boundaries belong to that presentation. It should be read as a historical dataset rather than as a measurement of current habits. A map also helps reveal location patterns, while a table makes exact labelled comparisons easier.
| Selected region | Displayed historical index |
|---|---|
| Rajasthan | −93 |
| Haryana | −81 |
| Punjab | −78 |
| Madhya Pradesh | −60 |
| Gujarat | −37 |
| Uttar Pradesh | −30 |
| Himachal Pradesh | −19 |
| Uttarakhand | −18 |
| Maharashtra | −15 |
| Bihar | +3 |
| Kerala | +79 |
| Tamil Nadu | +85 |
| Meghalaya | +95 |
| Tripura | +96 |
| Mizoram | +97 |
| Nagaland | +99 |
| Manipur | +100 |
Problem
Does Manipur’s displayed value +100 mean nobody there consumes wheat?
- 1.The legend describes a comparison derived from per-person rice and wheat consumption.
- 2.A positive extreme represents strong relative preference towards rice on this mapped scale.
- 3.It is not a statement that wheat consumption equals zero.
- 4.The graph also does not say that every individual makes the same food choice.
Problem
Use the selected-region table to identify the five strongest rice-side values and the region nearest balance.
- 1.Read the largest positive values: Manipur +100, Nagaland +99, Mizoram +97, Tripura +96, and Meghalaya +95.
- 2.These are the five strongest rice-side values in the table.
- 3.For balance, compare distance from zero rather than comparing signed values directly.
- 4.Bihar at +3 is nearest zero in the selected table, so its mapped comparison is closest to balanced.
A hidden number cannot usually be recovered exactly from a shade. In the source map, Karnataka’s label is hidden but its colour lies on the rice side. Comparing nearby shades can suggest an approximate range, but a precise value requires the underlying data. Avoid turning a colour estimate into an exact calculation.
What Can a Strip Say?
A day contains 24 hours. If each cell represents half an hour, a full day needs 48 cells. Colour each cell according to the activity during that interval and add a legend. You can then see both how long activities last and when they occur.
For a simple model, assign each interval one main activity so that the total remains 24 hours. If activities overlap, such as travelling while reading, decide on a consistent rule. Counting the same half hour twice would make the day longer than it really was.
Problem
In the example weekday, Study occupies 14 half-hour cells. How long is that, and what fraction of the day is it?
- 1.Multiply 14 cells by 0.5 hour per cell to get 7 hours.
- 2.Compare with the full 24-hour day: the fraction is 7/24.
- 3.As a percentage, 7 ÷ 24 × 100 ≈ 29.2%.
- 4.The cells include all intervals assigned to Study in this model, not just time spent inside school.
Problem
An activity begins at 09:00 and occupies six consecutive half-hour cells. When does it end?
- 1.Six cells represent 6 × 30 = 180 minutes, or 3 hours.
- 2.Add 3 hours to the starting time of 09:00.
- 3.The activity ends at 12:00.
- 4.Count the intervals between boundaries; counting both end labels as extra cells would overstate the duration.
Comparing Days and People
In the example strips, the weekday has 18 sleep cells and the vacation day has 20. Their sleep durations are 9 and 10 hours. The weekday has 14 Study cells, while the vacation day has 4, giving 7 and 2 hours respectively.
These are constructed examples for learning to read strips, not instructions for how every student should spend a day. Your own categories and timing may differ. When comparing a student and an adult, use the same cell length and definitions so differences are meaningful.
Make Your Own Activity Strip
Record a weekday and a holiday using a common set of categories.
- Draw 48 cells for each day and label a few time boundaries.
- Choose one main activity for each interval and colour it using your legend.
- Count the cells in every category and confirm that the counts sum to 48.
- Convert each category count to hours and compare the two days.
A complete strip should account for all 24 hours. A category total can tell you duration, but only the ordered strip tells you when that activity happened.
A comparison index is not automatically a percentage. In time strips, count intervals rather than boundary labels, and make sure all category durations together total one day.
Quiz
What does a value near zero mean on the rice–wheat index?
How many half-hour cells represent a full day?
How long is 7 half-hour cells?
An activity occupies 8 cells starting at 14:00. When does it end?
Can a hidden map value usually be recovered exactly from its colour?
The scale’s centre represents a relatively balanced mapped comparison, not zero consumption.
Practice Problems
- Which is closer to balance on the displayed scale: −15 or +3? Explain.
- A region has index −60. Can you say 60% of its people eat only wheat?
- A daily strip has 17 sleep cells, 13 study cells, 4 meal cells, and 14 other cells. Check the total and find sleep time.
- An interval from 18:30 to 20:00 covers how many half-hour cells?
- Compare study duration in the two displayed example strips.
- Two strips show the same category totals. Must their activities happen at the same times?
Step 1: Compare distances from zero: 15 and 3. Step 2: The value +3 is closer to zero and therefore nearer the scale’s balanced point.
Key Takeaways
• Read an infographic’s legend and the definition of its measure. • The rice–wheat index is a relative comparison, not an individual food-choice percentage. • A full day contains 48 half-hour intervals. • Category totals show duration; their positions show timing. • Use consistent categories and avoid counting the same interval twice.