Accuracy And Precision Difference: Introduction, Types, Examples, FAQs

Edited By Team Careers360 | Updated on Jan 28, 2024 09:22 PM IST

Introduction

Measurement has become a very important part of our life because it helps us to understand many things of the external world, and since millions of years of living, we have been able to make a sense of measurement. For measurements, some specific tools are required that provide us and scientists with a fixed quantity. But here the main problem is that every measurement done by any of the instruments has some error. While taking measurements of something, two important factors are considered which are Accuracy and Precision. Accuracy and Precision both of these measures how close we are to the real value of that factor.

This Story also Contains

Accuracy and Its Types
Precision and Its Types
Difference Between Accuracy and Precision
Examples of Accuracy and Precision :-

Accuracy and Its Types

Accuracy is an ability of any measuring instrument to find the real value or accurate value. We can also say that the closeness of value measured by instruments to the real value or true value is known as accuracy. On taking the small measurements, the errors of the calculation can be reduced so we can bring accuracy by taking small measurements. The accuracy in measurement of the subject is divided into three types as given below:

1. Point Accuracy :-

Point accuracy is defined as the accuracy of the measurement taken by an instrument at a specific point on its scale. This type of accuracy does not give any explanation about the common accuracy point of the instrument.

2. Accuracy as Percentage of the Scale Range :-

The accuracy of any measurement taken by an instrument is determined by the continuous scale. It is percentage-type accuracy.

3. Accuracy as Percentage of the True Value :-

This type of accuracy of the measuring instruments is determined by comparing the value that is measured by the instrument and the true value of that subject. ±0.5 percent of error of the instrumental measurement is neglected which varies from their true value.

Precision and Its Types

The nearness between two or more values of measurements to each other is called the precision of that substance. For example, if the weight of a given substance after weighing five times comes out as 3.2 kg each time, then the value of the measurement is very precise but may not be accurate. Precision is not depend on accuracy. Precision is divided into two categories :

1. Repeatability :-

When the measurements are taken repeatedly over a small period of time and the conditions are also kept the same then the variation that arises is known as rerepeatability.

2. Reproducibility :-

This type of variation arises in measurement when the measurements are taken in the same condition but by using different equipment and instruments for a long period of time.

Difference Between Accuracy and Precision

There are many differences between accuracy and precision that are discussed below :

Accuracy	Precision
The term tells us that the relation between the true value and the measured value of the substance is known as accuracy.	The level of variation that exists between two or more values of measurements of the same substance is known as precision.
To find the accuracy, only one value of measurement of the substance is required.	To find the precision, two or more than two values of measurements of the substance are required.
Accuracy represents how close the measured value of substance is to the actual value of the substance.	Precision represents how close the several measured values are with each other.
To get a measurement result continuously accurate at that point, it should be precise also at that point.	To get the precise result, there is no need to be accurate and also the results can be precise even with the accuracy.

Examples of Accuracy and Precision :-

If the temperature of the weather measured by the thermometer is 28°C and the real temperature is also 28°C, then this reading of the thermometer is accurate. Also if after measuring continuously for various days and the measurement is still 28 °C then this is said to be precise.
The best example to understand the accuracy and precision, is a football player who is shooting the ball at the goal. When the football player shoots the ball into the goal, it would be accurate. And if a football player continuously shoots at the same goal post then it can be precise but it can not be accurate. Hence, if a football player hits the ball at any place but still he scores then he is accurate without being precise. A football player who will hit the ball to the same place continuously whether he can score or not, he is precise. A football player who is both precise and accurate will not only hit the ball at the same spot but also he scores.
On taking the measurement of the mass of a body of 20 kg weight and the measured values by the scale are 17.4,17,17.3 and 17.1, hence your weighing scale is precise but is not accurate. If your weighing scale gives you the measurement values of 19.8, 20.5, 21.0, and 19.6, then it is more accurate but these values are precise.