Accuracy vs Precision

[Matlynn Giles 2E]

I found it really helpful the example Dr. Lavelle gave for Accuracy vs Precision. For me, it helped to think "Accuracy is how exact you are" and "Precision is how much of a pattern there is." Hope this helps!

[Shrinidhy Srinivas 3L]

This is super helpful! Thank you!

[Yasmina Zaarour 1G]

This does help! However, with that in mind, why are measuring tools and significant figures labelled with a certain "precision" if precision is how close multiple measurements are to each other?

[Lucy_Balish_3G]

Yes, I agree. That was super helpful!! For me the way I try to remember is "precision means consistent" and "accuracy means correct".

[Shrinidhy Srinivas 3L]

Measuring tools usually have the aspect of precision because it represents how close to the actual answer the measurement will be. It shows how close together the results will be, which makes sense according to the definition of precision.

[John Calonia 1D]

I believe they are labelled that way to show how reproducible the results they come up with are. I think of precision as reproducibility or how close together the results are from multiple tests. A measuring instrument can be completely uncalibrated, but if the results are all close together, you still know its a precise measurement.

[Kiran Singh 3A]

I agree! I found the target example helpful too, as accuracy would be hitting the small red circle in the middle and precision would be consistently hitting one place on the target.

[Megan Hulsy 1A]

I agree with this! I like how you portray precision as pattern and accuracy as exact, since this was somewhat difficult for me to understand. The target example was helpful for me as well.

[Keeryth Sandhu 1H]

I agree! The target example was really helpful in explaining that precision is more about consistency where accuracy is about correctness.

[Leyna Tran 2D]

Thank you! This is helpful to me in remembering the differences between the two! Precision, Pattern, Persistency- 3 P's. The target example also really helped me to be able to visualize the differences. The goal is hit the bullseye, so the darts that hit it are accurate. As the previous post mentioned, it is about "correctness."

[emmaferry2D]

The bullseye metaphor that Lavelle used in the pre recorded lecture helped clarify the concept, so if y'all are having a hard time grasping that I suggest watching that part again! Basically he explains that accuracy is like hitting the dart board close to the bullseye even if there are not consistent shots. He describes precision as hitting the dart board in the same spot consistently even if it is not near the bullseye.

[Evelyn Silva 3J]

Yes I agree! When he showed us the target pictures in the lecture it helped me visualize what he was trying to explain and understand the difference between the two.

[BKoh_2E]

The analogies they have given are really good. Accuracy is how close the measurement is to the correct value, while precision is how close a group of measurement are to each other.

[Jiapeng Han 1C]

Accuracy is how close you are to the real/true value. Precision is how close your experimental data is to each other. For example, let's say you want to measure the length of your pencil which is 15cm long and you measure 3 times. If you get 15.1cm, 15.0cm, 14.9cm, then you are both accurate and precise. However, if you get 14.1cm, 13.9cm, 14.0cm, then you are only precise because the data is close to each other.

[Bailey Giovanoli 1L]

I’ve always struggled with the difference between the two. I didn’t catch this in the lecture. Thank you for posting this, I’ll surely remember this from now on.

[Becca Nelson 3F]

There are major implications of accuracy and precision in the lab. Precision is one of the main reasons we have significant figures. Our resulting value needs to reflect the instrument with the most error that we used. We want other scientists to see how precise our data is which is a reflection of how precise our lab equipment is. It is incredible how such a fundamental idea is used in all chemistry!

[Nhu Pham-Dis3G]

With the definitions of accuracy and precision in mind, in what cases or scenarios would it be more useful to determine the accuracy/ precision? Is one more beneficial than the other in general, or does it solely depend on the situation?

[Neel Bonthala 2G]

With the definitions of accuracy and precision in mind, in what cases or scenarios would it be more useful to determine the accuracy/ precision? Is one more beneficial than the other in general, or does it solely depend on the situation?

I think accuracy more often than not trumps precision when it comes to obtaining correct data. However, in the context of an experiment, I'd say that precision is incredibly important, because variations in data from trial to trial can discredit the validity of an experiment. Ultimately, I think accuracy is more beneficial, although I think it should work with precision to obtain the best data possible :)

[Charmaine Ng 2D]

With the definitions of accuracy and precision in mind, in what cases or scenarios would it be more useful to determine the accuracy/ precision? Is one more beneficial than the other in general, or does it solely depend on the situation?

When conducting experiments, I think that accuracy is perhaps more valuable, since you can still gain a general conclusion or understanding of the experiment. However, mentality-wise, I think that scientists should not approach experiment prioritizing one over the other.The most desirable result would be to aim for both the most accurate and most precise results. Accuracy without precision or precision without accuracy still create flaws within experiments, and so both are important when conducting experiments! :))

[jessicasilverstein1F]

Another super helpful way to think about it is shown in the bullseye picture that Professor Lavelle elaborated on in his first lecture! Very helpful for visual learners.

[Rich Luong 1D]

To truly help remember, precision is that the values are very close to one another and accuracy is that the values are very close to the true value of whatever is trying to be found.