gcsescience.com                                       3                                       gcsescience.com

How Science Works

Evidence must be Reliable and Valid.

Data is said to be reliable if it is reproducible
by both yourself and others.
Reproducible means that if you keep repeating the
same experiment then you keep getting the same answers.
If you keep getting different answers
then the data is not reliable and can't be used as evidence.

Valid means that the evidence is both reliable and relevant.
Relevant means that the evidence gives you particular information
about the thing you are investigating, not just any information.
If you were investigating how a car moves or how a kite flies
then evidence about its weight would be relevant
but evidence about its colour would not be relevant.

Evidence which is reliable and valid can be used
to make scientific statements about things which are correct.
These statements are called conclusions.

Correct conclusions can give information about how
a particular phenomenon works.
The way that the conclusions relate to each other
is called a theory. A theory can be used to predict how
other phenomena work before investigating them.
A prediction based on existing scientific knowledge
and understanding is called a hypothesis.

So how do we get the evidence?

back       Links       How Science Works       Revision Questions       next

gcsescience.com         Chemistry Index         Physics Index         gcsescience.com

Home      GCSE Chemistry      GCSE Physics

Copyright © 2015 gcsescience.com. All Rights Reserved.