Difference Between Accuracy and Precision

Difference Between Accuracy and Precision

Most of us are required to measure a variety of materials and ensure they are as per the various norms. While we are taking the measurements, we have to be very careful. It depends on the person who is taking the measurement as well as the apparatus that is used to do the measuring. It is required that the readings are always correct and needs to be similar all the time.

If it is not so, then there is an error in the data. The person who is doing the measurements has to follow a proper process to ensure that the final reading is correct. To ensure this, the necessary steps are taken. The same measurement may need to be taken a number of times to ensure that the correct reading is taken.

While the people who are taking the measurements of the material know about the difference between accuracy and precision, we should also know what it is all about. It will be easier for us to talk to the people in the laboratory. We should always avoid heated arguments only because we were not aware of some information.

Whenever we are doing any experiment or measuring some essential criteria, like the weather, we need to know how accurate or how precise the data is. It is because our information has a lot of effect on other variables as well. For example, if we are speaking about the weather, any error in the data may lead to a significant loss on the ground. So, we must know these terms as correctly as we can. It will help us to comprehend the incident correctly, and we provide the correct data to the person who is asking for it.

We may have heard and learnt about these terms in school. It was quite long back, and very of us are remembering this even today. However, we should know the meaning of the words that we are using during our discussion with others. As mentioned earlier, if we do not know the correct meaning of what we are talking, it may lead to flare up that is not needed. There have been cases where people had quarrelled with the technicians in the laboratory as they did not the accuracy and precision difference.

Hence, we would need to ensure we know whatever we are saying as words once spoken cannot be taken back. We have always hoped that our readers can have a clear knowledge of what they are saying and what they are writing. We research the terms that people otherwise know have the same meaning, and then we provide the variances in their sense. In this article, we will look at the difference between accuracy and precision.

Definition of Accuracy

Accuracy is how near the measurement is to the correct one. It happens that while we are manually doing an experiment, the figure that we finally arrive at may not be the correct one. So, the measurement has to be taken quite a number of times. While taking the measurement, it can happen that the reading that is coming may be above or below the correct reading.  But the accuracy will say how near it is to the real reading. The technician will then comprehend whether the process is correct or not.

Now, when we are getting to know what is the difference between accuracy and precision, let us look at an example. Let us assume that we measure the temperature of an object, and it is thirty-eight degrees. In the experiment, the values that are determined are 37.9, 38.3, 38.1, 37.8 and 37.8; then we can say that this is a very accurate experiment. It is because it is close to the real value as much as possible.

We will now see another example. We assume that we measure an object. The correct weight is assumed to be fifty kilos. The weights that were measured are 47.82, 47.92, 47.85, 47.90 and 47.83. After these results have been received, we can now say that the readings are not accurate. This is because they are nowhere near the correct figure.

We are in the course of knowing what’s the difference between accuracy and precision. We now know that accuracy will be how much close the readings are to the actual value. It is a very important result area for measurement as it will allow us to know whether the apparatus with which the measurements are being taken is good or not.

Else, if the apparatus is giving wrong data, then the information provided will not be accurate, and other people will be required to face the effects. The term is applicable for measurements for high values items as well as items of lower value also. This clearly means that we need to treat the measurement in the cockpit of your car with the same degree while doing an experiment in the laboratory.

Definition of Precision

Precision is the procedure that allows the same value to be provided over and over again. When we are talking about precision, we are saying the processes are able to provide the same values over and over again. Usually associated with a highly accurate set of results, what is unique with precision is that you can also not be accurate if you are being precise. When you are acting with precision, you are providing very uniform and being repetitive in the measurements. 

Let us look at difference between precision and accuracy with a short example. When we are kicking the football, and we are near to the goal or scoring a goal, we are being accurate. Again, when we are even shooting away from the goal but always at the same place; the precision is very high. We are hitting the same area every time, but we are away from the goal.

People who are a bit scholarly will say that precision and accuracy will go hand in hand. In real life, this is not so. As mentioned in the above example, there can be cases when the person was totally inaccurate by shooting away from goal; he was shooting in precision as the ball was going to the same area every time he kicked. A precision measurement will ensure that all of the individually measured objects have a measurement that is near to each other.

Let us now also look at the difference between accuracy and precision in chemistry. When you are trying to do a chemistry experiment in the laboratory and the reading are very near to the correct value; you are being accurate. However, it can also happen that the readings were very near to each other; then you did the experiment with precision. The point here is that you could even go wrong in the experiment and the readings could be wrong but near to each other. Here, you were inaccurate, but there was precision.

The terms are used a lot in science and technology. As per the ISO, it is the measure of consistent as well as true results. So, they prefer the word accurate to be used only when the processes are both accurate and precise.

Accuracy vs Precision Comparison Table

Let us now know what’s the difference between precision and accuracy in a tabular form.

Basis of ComparisonPrecisionAccuracy
What it means It shows how near are the results to each other It shows whether the results agree to the correct value
Nearness to the correct value It does not necessarily mean it is near to the correct valueIt is near to the correct value
What type of error it is concerned with It is concerned about an error that is random It is concerned about the error that is systematic
What is represented Are the results close to one another Do the results tally with the standard value

Conclusion of the Main Difference Between Accuracy vs Precision

We had been discussing what is the difference between precision and accuracy. The basic variance between the terms is that when you are having the results that are very near to the correct value; then you are accurate. If your results are very close to each other; then you are doing the experiment with precision, but it may not be accurate.

Anyone is accurate only when the results agree with the correct value; you are in precision even if the results are close to each other. The results need not be near the correct value in order to be in precision.

It has been recently argued that the results must both be accurate and with precision at the same time. This argument holds merit for any experiment as the results need to be as correct as possible. There could be serious adverse effects if the results are wrong.

We sincerely hope that our readers will now be able to know the variance between the two terms. We will also continue to provide you with information to help you with the jargon. We will look forward to your comments.