Glossary

An investigation where one variable (the independent variable) is changed and all other conditions (controlled variables) are kept the same; what is measured or observed is referred to as the dependent variable.

well-known; something that a student has encountered previously on a number of occasions.

An observational or practical research undertaken in a normal environment of the subject of a study, that is, an investigation can be conducted outside the laboratory.

A push or pull between objects, which may cause one or both objects to change speed and/or direction of their motion (that is, accelerate) or change their shape. Scientists identify four fundamental forces: gravitational, electromagnetic (involving both electrostatic and magnetic forces), weak nuclear forces and strong nuclear forces. All interactions between matter can be explained as an action of one or a combination of the four fundamental forces.

Measurement based on an agreed standard unit (metre, second, gram).

A unit of measurement based on an agreed fixed standard (metre, second, gram).