# Cluster sampling

A method of sampling a population where you

Divide into sub categories

One or more categories chosen. Everyone is sampled in the chosen categories (also known as one-stage cluster sampling).

To summarise, think: Everyone in a couple of categories.

To remember this think of the following:

1. Divide into clusters

The hamster tried to eat all the nut clusters but only managed two of them before she was stuffed. She couldn’t get any more in.

**Example**

These are the results of a survey to see what percentage of people would attend a cinema screening of a live gig by a band.

There are 16000 people in the town. How many 15 to 18-year-olds would have to be surveyed if you used cluster sampling?

**Answer:**

15% of 16000 would have to be questioned for cluster sampling.

Therefore `15times16000/100=2400`