In this GCSE Biology quiz we look at precision of data. Precision is a measure of repeatability or reproducibility of scientific measurements. It is the degree to which repeated measurements, under the same experimental conditions, give the same result.
Accuracy is not the same thing as precision. Accuracy is about measurements being as close to the true value as possible. Precision is the measurement being the same value each time the experiment is performed. A measurement system can be accurate but not reliable (precise) or vice versa.
Precision is written as a percentage. It tells you how precisely you can use a piece of equipment to take a reading. It is calculated by subtracting the maximum percentage error from 100%.