Variables, variables, variables...
We often hear this word called 'variable' in an experiment, but what exactly is it? A variable is an item, factor or condition that could be changed or controlled. We often hear this word in experiments because experiments are created to find the relationship between how and why different variables affect each other.
There are also three main types of variables:
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Independent variable: the variable that is changed
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Dependent variable: the variable that is measured or observed
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Controlled variable: the variable that is controlled
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How do we design a fair test (experiment)?
A fair test is a test that changes the independent variable while the controlled variables are kept the same. It is important so you could get more accurate results from your experiments.
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Now, how do we carry out a fair test?
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To carry out a fair test, you simply need to KEEP THE CONTROLLED VARIABLES THE SAME. This is because when you change one factor in your test (the independent variable), you don't want the other variables affecting your results and making them inaccurate!
*About the image above (a little disclaimer):
For our experiment, you don't need to wear a lab coat and googles unless you are working in a lab! If you are working in the kitchen instead (which probably most people now are), just wear proper shoes, an apron, clean clothes and tie your hair back if it goes beyond shoulder length.
How to carry out an experiment safely and accurately to get valid data?
Here are some tips you might want to follow while trying out our experiment in the video later (safely, accurately and validly)...
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Repeat your experiment a few times so you could get a more valid result
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The more the merrier: it is best to work with an adult or a supervisor - especially when you are unfamiliar with the equipment. Safety first!!!
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Make sure you are wearing the right clothing and accessories for the experiment, whether it be googles and lab coats (when you're in the laboratory) or aprons (when you're in the kitchen). Also, if your hair is longer, tie it back - we don't want your hair to catch on fire or have your hair stuck somewhere uncomfortable!
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Wherever you're carrying out your experiment, clear the path and make sure your workspace is neat; by doing this, you'll reduce the confusion and prevent accidents from happening.
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Make sure your equipment is working properly - you don't want inaccurate results!
So finally, the conclusion!
A conclusion often sums up the following:
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What you have learnt from the experiment
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Whether the experiment supports your prediction of the experiment (your hypothesis)
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Include some of the data that either supports or goes against your hypothesis - make sure the data you include is relevant!
