Experimental Design Process – Errors

Sources of Error

Even when every effort is made to keep all controlled variables constant, errors can occur while conducting an experiment.

The aim of any experiment is to ensure results are fair, replicable, accurate and precise. 

A good analogy for observing the difference between accuracy and precision is the dart board example, as outlined below.

(Image Source: https://i.stack.imgur.com/LGTLQ.png)

Two main categories of error are Systematic Error and Random Error.

Systematic Error is a type of error that occurs consistently throughout the experiment. Results obtained when systematic errors are present could still be precise, but not necessarily accurate. 

Random Error is a type of error that occurs inconsistently throughout the experiment. Results obtained when random errors are present may be either precise or not precise, but not necessarily accurate.