Main Difference – Accuracy vs Precision
Accuracy and Precision are important concepts when talking about measurements. Although these two concepts are often interrelated, there is a marked difference between the two and the presence of one does not ensure the other, i.e., accuracy and precision are independent of each other. The main difference between accuracy and precision is that accuracy specifies how close a measurement is to the correct or accepted value whereas precision specifies the closeness of two or more measurements to each other.
What is Accuracy
Accuracy is “the degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard.” In other words, accuracy specifies how close a measurement is to the accepted or correct value. Accuracy is getting a value that is close to the real value. For example, if you obtain a weight measurement of 3.2 kg value while the real value is 3.2, your measurement is accurate. Similarly, if you hit a bull’s eye in a shooting competition, your aim is accurate. Let’s look at another example to clarify the meaning of accuracy. Imagine a game of basketball; if the player shoots the ball into the or close to the basket, he is shooting with accuracy. But accuracy is not the only thing that will help him to win the game; he’ll also need precision. Now, let’s look what precision is.
What is Precision
Precision is “the refinement in a measurement, calculation, or specification, especially as represented by the number of digits given.” In other words, precision indicates the closeness of two or more measurements to each other. If you are getting similar measurements each time you measure, then your measurements are precise.
Let’s briefly look at the above-discussed examples and see how precision can be applied to them. If you measure the object five times and get the measurement 3.2 kg every single time, then your measurement is precise. Similarly, if you are in a shooting competition, and you hit the same spot every time, your aim is precise.
However, it is also important to remember that accuracy and precision are two independent concepts. Accuracy does not automatically imply precision. For example, you might have accuracy, but not precision. You may hit the bulls eye once, but after that, your aim may wander. Similarly, you might hit the same spot, but it may be distant from the bulls eye. Here, you have precision, but not accuracy.
Low accuracy, good precision
Difference Between Accuracy and Precision
Function
Accuracy: This indicates how close a measurement is to the correct or accepted value.
Precision: This indicates the closeness of two or more measurements to each other.
Measurement
Accuracy: Your measurement will be close to the standard measurement.
Precision: Your measurement will be similar every time you measure.
Interdependence
Accuracy: Accuracy is not dependent on precision.
Precision: Precision is not dependent on accuracy.
Image Courtesy:
“High precision Low accuracy” By DarkEvil – DarkEvil, based on Image:Accuracy and precision-highprecisionlowaccuracy.gif which is free.(Public Domain) via Commons Wikimedia
Image 2 (Public Domain) via Pixbay
