# Variable

## Key Stage 2

### Meaning

A variable is something that you can change, keep the same, or measure/observe in an investigation.

There are three types of variable.
In an experiment or investigation there should only be 1 independent variable. If you change more than one thing at a time, it is not a fair test.

### Examples

An investigation to test the claim: All leaves are green.

 Oak Leaf Beech Leaf Ash Leaf Maple Leaf Chestnut Leaf Variables The type of leaf chosen was the independent variable. The colour of the leaves was the dependent variable The experiment was done at the same time of year for every tree because at different times leaves can change colour or fall off. This was a control variable
 Results Table Variables The type of food chosen was the independent variable. The colour of the iodine after being added to food was the dependent variable. There are many control variables that should be done. If the food colour was blue or black it might give the wrong result, so all the food should be the same pale colour. Another control variable is the amount of iodine used.
 Experiment Variables Cress seeds were put in pots with soil with half placed in a dark cupboard and half on a windowsill. Independent Variable: Where you chose to put the cress seeds. Dependent Variable: The observations of the cress seeds. Control Variable: How long you left them for. They should all be left for the same amount of time or it's not a fair test. Control Variable: How much you watered them. They should both be watered the same amount to make it a fair test.

## Key Stage 3

### Meaning

A variable is anything which could affect the results of an experiment or that you can change, keep the same, or measure/observe in an investigation.

There are three groups of variable in an experiment:
In an experiment or investigation there should only be 1 independent variable. If you change more than one thing at a time, it is not a fair test.

## Key Stage 4

### Meaning

A variable is anything which could affect the results of an experiment or that you can change, keep the same, or measure/observe in an investigation.

There are three groups of variable in an experiment:
In an experiment or investigation there should only be 1 independent variable. If you change more than one thing at a time, it is not a fair test.
There are three different types of variable which can be recorded in an experiment:

### References

#### AQA

Variables page 9, GCSE Combined Science Trilogy; Physics, CGP, AQA
Variables, page 10, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA
Variables, page 118, GCSE Biology, Hodder, AQA
Variables, page 370-1, GCSE Biology; Student Book, Collins, AQA
Variables, page 4, GCSE Biology; The Revision Guide, CGP, AQA
Variables, page 4, GCSE Combined Science; The Revision Guide, CGP, AQA
Variables, page 4, GCSE Physics; The Revision Guide, CGP, AQA
Variables, pages 10, 16, GCSE Chemistry, CGP, AQA
Variables, pages 10, 16, GCSE Combined Science Trilogy; Chemistry, CGP, AQA
Variables, pages 103, 241-2, GCSE Combined Science Trilogy 1, Hodder, AQA
Variables, pages 144-5, GCSE Chemistry, Hodder, AQA
Variables, pages 17-18, 178, GCSE Physics, Hodder, AQA
Variables, pages 253, GCSE Combined Science Trilogy 2, Hodder, AQA
Variables, pages 264-265, GCSE Chemistry; Third Edition, Oxford University Press, AQA
Variables, pages 277-279, GCSE Physics; Third Edition, Oxford University Press, AQA
Variables, pages 5, 8, GCSE Chemistry; The Revision Guide, CGP, AQA

#### Edexcel

Variables, page 10, GCSE Biology, CGP, Edexcel
Variables, page 10, GCSE Physics, CGP, Edexcel
Variables, page 136, GCSE Chemistry, Pearson, Edexcel
Variables, page 4, GCSE Combined Science; The Revision Guide, CGP, Edexcel
Variables, page 5, GCSE Biology; The Revision Guide, CGP, Edexcel
Variables, page 5, GCSE Chemistry; The Revision Guide, CGP, Edexcel
Variables, page 5, GCSE Physics; The Revision Guide, CGP, Edexcel
Variables, pages 9-1, 16, 17, 20, 21, GCSE Chemistry, CGP, Edexcel

#### OCR

Variables, page 4, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR
Variables, page 5, Gateway GCSE Chemistry; The Revision Guide, CGP, OCR
Variables, pages 5, 8, Gateway GCSE Biology; The Revision Guide, CGP, OCR
Variables, pages 5, 8, Gateway GCSE Physics; The Revision Guide, CGP, OCR
Variables, pages 8, 12-15, 281-282, 288-289, Gateway GCSE Biology, Oxford, OCR
Variables, pages 8, 12-15, 282-283, 287-288, Gateway GCSE Physics, Oxford, OCR
Variables, pages 8, 14-15, 278, 296-297, 302-303, Gateway GCSE Chemistry, Oxford, OCR