What is the difference between accuracy and precision?

The majority of people are confused with the terms accuracy and precision. Some think both terms are the same and reflect the correction of the acceptable results. While doing fun with instruments in the laboratory, you have heard from your teacher about these terms and have observed while solving the errors that appeared during the experimental measurements. The question here is, are these both terms the same or different?

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Both terms are not the same at all, but you can say that these are relatively closed enough to confuse you. But with practice and correct knowledge, you will get the difference and find the way to define the terms on the basis of the difference between them.

Both terms are about the quality of the results you are seeking in a laboratory or in an office, finding them either they are acceptable or not if not, why? Are these results not up to the mark, or you do not like them? No, buddy, it depends on the analysis, the measurements to compare them with the correct and expected figures.

A guide on What is the Difference?

So, we can say that accuracy is the correction of measurement that is very close to the expected original or true value of that particular measurement. If we talk about the precision of a quantity, it does not belong to the true value of the quantity, but it is all about the result generated very close to each other. You may say there is no such distinct difference between the two points. 

What actual accuracy is?

Accuracy is the chances or degree of closeness of the results or measurements to the actual and real value of an object or a quantity. The accuracy of something may be based on the following points.

Actual value of something

Closeness to the reference point, such as mentioned in the arrow aiming game.

The actual or true value of something 

Suppose, if you are sitting in a hall and someone randomly asks you, hey, how many of you people are in the hall watching the movie? And you get surprised what kind of question is this, but you will reply with an estimate by saying, about 20. 

If the true numbers of people in the hall are 21 or 22, near value means you are almost following the accuracy, but if the number of people is varying to 25 or 30, it means you are very far from the true number of people sitting in the hall so, you are not following the accuracy. 

Closeness to the reference point 

Consider, you are participating in the competition in which you are supposed to shoot the targeted point on the board with a gun, or you have to shoot the balloons filled with water. If you shoot the right reference point or the exact balloon as you were asked to secure your position, you did an accurate job by showing accuracy to the reference point.

But if you lose to aim the target you were required to shoot, you are at bad of accuracy and lose your position.

What actually precision is?

Precision is all about consistency of the result showing how much the two or more results are closer to each other. Precision refers to the closeness of the outputs on the graph or values of something in the observational table showing the comparison of the values with each other. If the values after repetition are very close to each other regardless of their closeness to the actual value, then it is a precise effort towards your goal. 

IF you find random results or ups and downs on the graph showing an analysis of your performances or the performances of a machine, the precision level is bad.  It is divided into three basic parts, which are:

  • Repeating factor 
  • Reproductive factor
  • Repeating factor

Suppose, if you are doing a laboratory experiment and getting variable values, but these values are not so far from each other but roaming around the first value, then second, and so on, showing the continuation of the results near the same point. For example, the first measurement is 2cm, the second is 2.02, the third is 2.04, and it goes on with some repetition, which means the results are precise. 

Reproductive factor

It is about the use of different instruments you are using for the measurement of the same thing for obtaining the same or roundabout results.

What is the difference?

There is a need to discuss some parameters on which you people can easily differentiate independently. So, there are some parameters that define the properties.

The closeness of the results

If we talk about the accuracy, the results should be close to the actual value of a thing or quantity taken as a reference. Suppose, if you say 1-liter milk contains about 436 calories and after experiments using different approaches to find the results, you get 434 calories in one-liter milk. 

Your results are very close to the true value, so; you are very close to accuracy. But if the results are on the contrary, like you find a fair value that is much higher or lower than the actual value, it means you are not following accuracy and need improvement.

Let's move on with our debate on what is the difference Between accuracy & Precision?

Precision is somehow different in the case of the closeness of the results. It is also about closeness but not with reference to the actual or true value. Precision shows the closeness of the results with each other rather than the true value of a product.

Suppose if you measure the length of a table using a measuring tape three times, and you get variable values like 23.50 cm, 23.55 cm, and 23.75 cm. These all three values are very close to each other and lead to the precision of measurement. But in contrast, if the value were 23 cm, 33 cm, and 35 cm, then the measurements are not showing the precision. 

Representation of measurements 

The result-producing measurements are representing the actual value of the thing regardless of working independently with the measuring values. You may say that in case of accuracy, you always need a reference point and cannot take the initiative independently. The reference may be the value of something or a point, a spot to reach the accuracy to prove your skill or the accuracy of your instrument.

While if we talk about precision, we do not need to follow a pre-existing reference point or a reference value to prove ourselves. Here we are making our choices, but after aiming at a single target, we need to get in the flow of continuation by showing the results or outputs closer to each other but not randomly. 

It is important to discuss when we talk about What is the Difference Between Accuracy & Precision?

Good or bad results refer to 

Bad results may appear in both cases, but the conditions are different on which we decide either the results are good or bad. As we have discussed many times in this article, accuracy and precision both are different on the basis of following the reference of the pre-existing value of the thing or not. Accuracy of something is said to be good when you get the results closer to the actual value, while if the results show variability far from the actual value, we say that it does not show good results and accuracy is low.

While in case of precision, if the results are closer to each other, we use to say we get precise or good results concerning the precision, while if the results are far from each other and you cannot make them round to each other, or they are in scattered form, the results are said to be bad.

Quality dependence 

The accuracy only follows the reference value of something, so it does not tell us about the quality of the results but only shows accuracy with respect to the true value of the reference. While in the case of precision, it tells us about the quality of the results of the instruments someone is using. Suppose if you are using an instrument to measure the volume of liquid and it shows the result closer to each other, we may say the results are highly précised as they are maintaining the quality. 

Types of error that may occur

In the case of accuracy, we face systematic errors that appear due to the error in the instruments mostly. It lies linear to the instrument and may be of two different types depending upon the zero, while in the case of precision, random error takes place that is not in linear order and seems unpredictable. 

Systematic errors that occur in accuracy follow a proper series and continue throughout the process, while in case of random error, there is no continuity. It can occur any time, in any phase. 

Final Thoughts:

So, if you are looking to know what is the difference Between accuracy & Precision, then you should read the above guide to understand both terms and their differences better.

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