Data and Graphs: Recording What We See
Learn
Scientists collect data to learn about the world. Data is information we gather by observing, measuring, and counting. In this lesson, you will learn how to record your observations and show them in a graph.
What is Data?
Data is information we collect. When you measure how long a shadow is, you are collecting data. When you count how many sunny days there are in a week, you are collecting data too!
Ways to Record Data
- Tally marks: Quick marks to count things (IIII = 4)
- Tables: Organized rows and columns to sort information
- Drawings: Pictures that show what you observed
What is a Graph?
A graph is a picture that shows data. Graphs help us see patterns and compare information. A bar graph uses bars of different heights to show amounts.
Reading a Bar Graph
To read a bar graph:
- Look at the title to know what the graph is about
- Read the labels at the bottom (categories)
- Read the numbers on the side (amounts)
- Compare the heights of the bars
Examples
Example 1: Recording Shadow Length
Maria measured her shadow at different times. Here is her data table:
| Time | Shadow Length (in hands) |
|---|---|
| Morning (9 AM) | 8 hands |
| Noon (12 PM) | 3 hands |
| Afternoon (3 PM) | 7 hands |
Example 2: Weather Tally Chart
Leo tracked the weather for one week:
| Weather | Tally | Total |
|---|---|---|
| Sunny | IIII | 4 |
| Cloudy | II | 2 |
| Rainy | I | 1 |
Example 3: Reading a Bar Graph
This bar graph shows how many hours of daylight there are in different seasons:
Hours of Daylight by Season
The taller the bar, the more hours of daylight.
Which season has the most daylight? Summer (the tallest bar)
Practice
Complete these practice questions to check your understanding of data and graphs.
1. What is data?
Think about information scientists collect.
2. Name two ways to record data.
3. Look at Maria's shadow data above. When was her shadow the longest?
4. Look at Maria's shadow data. When was her shadow the shortest?
5. In Leo's weather tally chart, how many days were NOT sunny?
Add the cloudy days and rainy days together.
6. What does a bar graph use to show amounts?
7. Look at the daylight bar graph. Which season has the least daylight?
8. If you wanted to track the moon's shape for a month, would you use tally marks or drawings? Why?
9. Create a tally chart showing 3 sunny days, 2 cloudy days, and 1 rainy day.
10. Why do scientists use graphs to show their data?
Think about how graphs help us understand information.
11. If a bar in a graph is taller than another bar, what does that tell you?
12. You measure your shadow three times in one day. How would you organize this data?
Check Your Understanding
Answer these questions to make sure you understand the main ideas.
Key Idea 1: Data is ___________ we collect by observing, measuring, and counting.
Key Idea 2: A ___________ is a picture that shows data using bars of different heights.
Key Idea 3: Scientists use graphs to see ___________ and compare information.
Next Steps
- Practice making tally charts for things you observe at home
- Try creating a simple bar graph with crayons and paper
- Use your shadow investigation data to make a graph
- Continue to the next lesson to learn how to write about your findings