Somerville House Middle School Science On-line: Year Seven

Creating a Key

Theory
We classify things into groups to help us remember them, and see how they relate to each other.

The organisation of items in shops is a good example: Undies in one section, hardware in an other;
or even in completely different shops.
Visit the "Classification of living things" section of the XSIQ site and read sections 1 to 4 for more information.

When we group things, it is usually by their structure (how they are made) or their function (what they do or are used for).
We usually avoid using things like colour until the items are so similar we have no other features to use for separating them.

We create a key by asking questions about the organisms that have a yes or no answer.
This is called a dichotomous (two answers)key. You will have read about this on the XSIQ pages.

Practice
Create a flow chart to classify the contents of one of your group's pencil case.