A glossary of terms used in science investigations

Variables are characteristics which can change and have different values.

Parameters
In a 'fair test' all the variables, except the one being investigated, are kept constant. Sometimes these controlled variables are called 'parameters'.
If only one variable is allowed to alter then its effect on other variables can be found.

Independent variable
The variable that is being deliberately changed is called the independent variable

Dependent variable
The variable that changes as a result is called the dependent variable

Accuracy - whether the result (or average of the results) is close to the actual value

Precision - whether repeated data points are close together in value

Repeatable - when the expt. is repeated by the same person using the same equipment and the results are close together

Reproducible - when the expt. is carried out by a different person using different equipment and the results are close together.

Reliable - whether you consider that a result (or set of results) is likely to allow you to arrive at the 'correct' conclusion.