Understand the idea.
Two kinds of answer
Data are answers or observations we collect to find something out. A categorical answer names a group, such as apple or banana. A count answer tells how many objects or people there are.
A count can be : a bag with no books has zero books. Counts use whole numbers because we count complete objects. Height is different: we measure it, rather than count it.
Ask a clear question
A clear question helps everyone give the same kind of answer. Ask which one fruit each child would choose if you want one vote per child. Asking which fruits they like could give several answers each.
Decide what an answer means before naming its data type. A bus number identifies a bus route; it does not count passengers. Fruit names are categories, even when we later count how many children chose each fruit.
| Fruit | Children |
|---|---|
| Apple | 6 |
| Banana | 4 |
| Orange | 2 |
See the method in action.
A named group
Mia asks, “Which fruit would you choose: apple, banana or orange?” What kind of data will she collect?
Worked solution
- 1
Identify the possible answers.
Mia asks each child to name apple, banana or orange.
- 2
Classify what those answers tell us.
Each answer names a fruit group, rather than telling how many objects there are. The data are categorical.
Categorical data.
Counting objects
Jai records 3 books, 0 books and 5 books in three bags. What kind of data is this?
Worked solution
- 1
Read what each number describes.
These are numbers of books in the three bags, rather than labels on the bags.
- 2
Include the empty bag and name the data type.
No books is a count too. Every answer tells how many books a bag holds, so these are count data.
Count data.
Try it yourself.
Check your understanding
Is “number of pencils in a pencil case” categorical or count data?
Show answer & reasoning
Count data.
The answer counts the pencils in the case. It could be or another whole number, so it is count data.
Keep practising
6 worksheet questions
Read the questions online
- Is favourite sandwich filling categorical data or count data?
- Is the number of people in a family categorical data or count data?
- Write one possible answer to “How many pets live in your home?”
- Write one possible answer to “How do you usually travel to school?”
- Can 0 answer “How many books did you borrow?” Explain.
- A bus is labelled 12. Does 12 tell how many children are inside? Explain.
Read the worked solutions
- Is favourite sandwich filling categorical data or count data?
The answer names a filling, such as cheese.
Categorical data. - Is the number of people in a family categorical data or count data?
The answer counts people.
Count data. - Write one possible answer to “How many pets live in your home?”
An answer must be a whole-number count of pets.
For example, 2. Zero or another whole-number count is also possible. - Write one possible answer to “How do you usually travel to school?”
The answer names a way of travelling.
For example, walking. Car, bus or another clearly named way is also possible. - Can 0 answer “How many books did you borrow?” Explain.
Zero records an actual count rather than a missing answer.
Yes. It means no books were borrowed. - A bus is labelled 12. Does 12 tell how many children are inside? Explain.
A label does not count the passengers.
No. It is a route number or another bus identifier, not a passenger count.
Curriculum reference & lesson scope
Australian Curriculum v9 / South Australian Curriculum
Categorical/count data; recording; displays; comparisons; guided question-to-conclusion investigation.
Official curriculum source ↗