Data and Graphs: Recording Our Observations
Learn
Scientists do not just watch what happens - they write it down! When we record what we see and measure, we are collecting data. Data helps us remember our observations and share them with others.
What Is Data?
Data is information we collect during an experiment or observation. Data can be:
- Numbers: "The ice melted in 15 minutes."
- Words: "The water is clear and wet."
- Drawings: A picture of what we see.
Using a Data Table
A data table helps us organize our information. Here is an example from an ice melting experiment:
| Time (minutes) | What I See |
|---|---|
| 0 | Ice cube is solid, no water |
| 5 | A little water around the ice |
| 10 | Ice is smaller, more water |
| 15 | Ice is very small, lots of water |
| 20 | Ice is gone, only water left |
What Is a Graph?
A graph is a picture that shows data. Graphs help us see patterns and compare information quickly.
Picture Graph
A picture graph uses pictures or symbols to show data. Each picture stands for one item (or a number of items).
Example: Objects in our classroom sorted by state of matter
- Solids: [book] [book] [book] [book] [book] = 5 objects
- Liquids: [drop] [drop] = 2 objects
- Gases: [cloud] = 1 object (air in a balloon)
Bar Graph
A bar graph uses bars of different heights to show amounts. Taller bars mean bigger numbers.
Example: Time for ice to melt in different places
- Sunny window: [========] 10 minutes
- Kitchen table: [================] 20 minutes
- Refrigerator: [did not melt in 1 hour!]
Reading a Graph
When you look at a graph, ask yourself:
- What is the title? This tells you what the graph is about.
- What do the labels say? These tell you what is being counted or measured.
- What do the bars or pictures show? Count or compare them.
- What pattern do you see? Is one bigger? Did something change over time?
Examples
Example 1: Reading a Data Table
Look at this data table:
| Item | State of Matter |
|---|---|
| Apple | Solid |
| Milk | Liquid |
| Air in balloon | Gas |
| Pencil | Solid |
Question: How many solids are in the table?
Answer: There are 2 solids (apple and pencil).
Example 2: Understanding a Bar Graph
A bar graph shows how many objects are solids, liquids, or gases in Room 5.
- Solids bar reaches 8
- Liquids bar reaches 3
- Gases bar reaches 1
Question: Which state of matter has the most objects?
Answer: Solids have the most objects (8), because the Solids bar is the tallest.
Example 3: Collecting Data
Mia watched butter melt in a warm pan. She wrote down what she saw:
- Start: Butter is a solid block
- 30 seconds: Edges are soft and shiny
- 1 minute: Butter is mostly liquid
- 2 minutes: Butter is completely melted
Question: What type of data did Mia collect?
Answer: Mia collected word data (descriptions) and time data (numbers in seconds and minutes).
Practice
Use what you learned about data and graphs to answer these questions.
1. What is data?
- A) A type of solid
- B) Information we collect during experiments
- C) A kind of gas
- D) A toy
2. Which is an example of number data?
- A) "The water is blue."
- B) "The ice melted in 12 minutes."
- C) "I drew a picture of the ice."
- D) "The experiment was fun."
3. What does a data table help us do?
- A) Make the experiment longer
- B) Organize our information
- C) Turn water into ice
- D) Hide our observations
Use this picture graph to answer questions 4-6:
States of Matter in Our Kitchen
- Solids: [star] [star] [star] [star] [star] [star] = 6 items
- Liquids: [star] [star] [star] = 3 items
- Gases: [star] = 1 item
4. How many solid items are in the kitchen?
- A) 1
- B) 3
- C) 6
- D) 10
5. Which state of matter has the fewest items?
- A) Solids
- B) Liquids
- C) Gases
- D) They are all the same
6. How many more solids than liquids are there?
- A) 1
- B) 2
- C) 3
- D) 6
7. On a bar graph, what does a taller bar mean?
- A) A smaller number
- B) A bigger number
- C) The experiment is over
- D) The bar is broken
8. Jake watched ice melt. He checked it every 5 minutes and wrote down what he saw. Jake collected:
- A) No data
- B) Only word data
- C) Time data and word data
- D) Only picture data
9. Why do scientists make graphs?
- A) To make the experiment harder
- B) To see patterns and compare information easily
- C) To throw away their data
- D) To keep their work secret
10. What is the first thing you should look for when reading a graph?
- A) The smallest bar
- B) The title
- C) The colors
- D) How many pictures there are
Check Your Understanding
Think about these questions and discuss with a partner or adult.
- What are three ways we can record data? (Hint: numbers, words, and...)
- Why is it important for scientists to record their observations?
- What is the difference between a picture graph and a bar graph?
- If you did an experiment about how fast different liquids freeze, what data would you collect?
- How can looking at a graph help you understand an experiment better than just reading numbers?
Next Steps
- Create your own data table to record observations about matter at home
- Make a picture graph showing solids, liquids, and gases in your bedroom
- Practice reading graphs in books, magazines, or online
- Continue to the next lesson to learn about CER writing - explaining your scientific thinking