Can you score 2.5 goals?

You cannot score 2.5 goals. You score 2 or 3. But you can run 2.5 kilometres. And your team colour is not a number at all.

All three are data, but they are three different kinds. The kind decides what you can do with the data. In this lesson we also turn words into data a computer can count.

Key words

Word	What it means	Example
Discrete value	A number you count. It jumps from one whole number to the next.	Goals: 0, 1, 2, 3
Continuous value	A number you measure. It can be any value in a range, with decimals.	Height: 1.723 metres
Categorical value	A name of a group. You can count how many are in each group, but not add the names.	Red, blue, green
Codify	Turn words into a fixed set of codes or groups that a computer can count.	"The coach was late" becomes "transport"
Single object	Stored and read as one whole piece. You cannot search inside it without more work.	A photo or a comment
Structured data	Data in a fixed shape, such as rows and columns.	A table
Qualitative data	Data that describes in words, pictures or sound.	A comment
Quantitative data	Data that is a number.	5 stars

The cells students fill in are left blank in this preview.

Discrete: you count it

A discrete value is counted. There is a gap between one value and the next.

Goals, students, cars, brothers and sisters. You can have 2 or 3. You cannot have 2.5.

Continuous: you measure it

A continuous value is measured. It can be any value, even between two others.

Height, weight, time, temperature. 1.7 metres, 1.72 metres, 1.723 metres. How exact it is depends on the tool you use.

Categorical: you group it

A categorical value is the name of a group. Colour, country, bus route, year group.

You can count how many are in each group. You cannot add "red" and "blue". Careful: a bus route such as 42 looks like a number, but it is only a name.