Why accuracy, not precision?

[doubleh]

That actually surprises me. I was afraid I was going over old ground.

I have seen each term used to describe a rfle's capability but not debated before. I consider each term when used in a shooting context to basically mean "I have a rifle that's capable of putting it's shots really close together repeatedly" but that's probably not an accurate or precision defination.

 

[buck460XVR]

I didn’t decree that. It is just the way it is.

Similar to the use of the word accuracy. But you chose to decree it as being wrong, altho it is the centuries long accepted correct colloquial terminology. So my question is, Why precision and not accuracy?

Just sayin'.

Your complaint about those who would gratuitously educate us in areas we are ignorant reminds me of the old admonishment to children that we associate with Appalachian parents fairly or otherwise: “Don’t get above your raisin’.” How uplifting!

The definition says it all.......
gra·tu·i·tous·ly
ɡrəˈt(y)o͞oədəslē/
adverb
adverb: gratuitously
1.
without good reason; unjustifiably.

....just as one can say "Don't get above your raisin", one can also say , "no need to look down your nose at others"., or "get off you high horse".

Again, regardless of which term one uses, folks in the gun world know what we are talking about. They are not confused. Like I said before, lot a stirrin' goin' on, for an empty pot.

This discussion, while being fun, has been useless, other than showing us that very few folks give a hoot about it. Probably the best answer to your original question.

 

[rpenmanparker]

Similar to the use of the word accuracy. But you chose to decree it as being wrong, altho it is the centuries long accepted correct colloquial terminology. So my question is, Why precision and not accuracy?

Just sayin'.



The definition says it all.......
gra·tu·i·tous·ly
ɡrəˈt(y)o͞oədəslē/
adverb
adverb: gratuitously
1.
without good reason; unjustifiably.

....just as one can say "Don't get above your raisin", one can also say , "no need to look down your nose at others"., or "get off you high horse".

Again, regardless of which term one uses, folks in the gun world know what we are talking about. They are not confused. Like I said before, lot a stirrin' goin' on, for an empty pot.

This discussion, while being fun, has been useless, other than showing us that very few folks give a hoot about it. Probably the best answer to your original question.

Just take some new knowledge and use it if you can, and don’t if you can’t. It won’t hurt you either way.

 

[ford8nr]

Can't believe we're still talkin' about this.

Guess what I did yesterday, got out and SHOT a High Power Short Course event. No debating vocabulary, just shootin' and adjusting sights. Irons at 200 - great fun!

 

[Pete D.]

Attached is a picture of a three shot group that I shot for a muzzleloading rifle match. Three shots at the center of a blank piece of paper. Benched. Iron sights only. 100 yards.
I was happy with the group. I see it as an example of fairly precise shooting with that old Lyman.
It was the best group fired in that match. I lost.
Why? Because the center of the target is the X and the idea was to get three shot as close as possible to the X, another fellow shot a larger group but each shot was closer to the center than mine. More accurate.

 

[rpenmanparker]

View attachment 788294 Attached is a picture of a three shot group that I shot for a muzzleloading rifle match. Three shots at the center of a blank piece of paper. Benched. Iron sights only. 100 yards.
I was happy with the group. I see it as an example of fairly precise shooting with that old Lyman.
It was the best group fired in that match. I lost.
Why? Because the center of the target is the X and the idea was to get three shot as close as possible to the X, another fellow shot a larger group but each shot was closer to the center than mine. More accurate.

Pete, this is such a good example. How would we discuss this without the right lingo?

 

[KansasSasquatch]

To be precise is to be exact. To be accurate is to be repeatedly within a given range of precision.

So hitting the dead center of a bullseye is being precise. Repeatedly hitting the bullseye is being accurate. So given those definitions accuracy is typically more important in the realm of firearms. If a bullseye is always worth the same number of points, who cares if you hit dead center of the bullseye or just a little off from dead center if you can repeatedly hit just slightly off?

 

[rpenmanparker]

To be precise is to be exact. To be accurate is to be repeatedly within a given range of precision.

So hitting the dead center of a bullseye is being precise. Repeatedly hitting the bullseye is being accurate. So given those definitions accuracy is typically more important in the realm of firearms. If a bullseye is always worth the same number of points, who cares if you hit dead center of the bullseye or just a little off from dead center if you can repeatedly hit just slightly off?

Your understanding of the terms is exactly backwards.

 

[ford8nr]

Hey, I just got my new grips and trigger kit for my new Ruger Mk IV. Tonight I'm gonna install them and tomorrow I'm gonna go SHOOT it to see how accurate the gun is and how precise I can be.
Musta' been a long winter for some ...

 

[rpenmanparker]

Hey, I just got my new grips and trigger kit for my new Ruger Mk IV. Tonight I'm gonna install them and tomorrow I'm gonna go SHOOT it to see how accurate the gun is and how precise I can be.
Musta' been a long winter for some ...

Au contraire, mon frere. I shoot once or twice every week, and I just came back from a training course during which I burned through 650 rounds in four days. The truth is the truth and is not affected by snark.

 

[KansasSasquatch]

Your understanding of the terms is exactly backwards.

Sorry, but I have more trust in the dictionary definitions than I have in a random stranger's definitions. I clearly remember looking it up years ago when my high school chemistry teacher was explaining the difference.

http://www.dictionary.com/browse/accurate
http://www.dictionary.com/browse/precise?s=t
http://www.dictionary.com/browse/precision
http://www.dictionary.com/browse/accuracy

 

[rpenmanparker]

Sorry, but I have more trust in the dictionary definitions than I have in a random stranger's definitions. I clearly remember looking it up years ago when my high school chemistry teacher was explaining the difference.

http://www.dictionary.com/browse/accurate
http://www.dictionary.com/browse/precise?s=t
http://www.dictionary.com/browse/precision
http://www.dictionary.com/browse/accuracy

The dictionary is wrong too. Sometimes that is just the way it is. I am not a random stranger but an expert in experimental design and performance and data management. Any physical scientist will validate my statements.

 

[rpenmanparker]

Here is a more knowledgeable resource than an online dictionary:
http://blog.minitab.com/blog/real-w...nt/accuracy-vs-precision-whats-the-difference

And here is the seminal quotation from the above resource:
"Accuracy refers to how close measurements are to the 'true' value, while precision refers to how close measurements are to each other."

 

[KansasSasquatch]

The dictionary is wrong too. Sometimes that is just the way it is. I am not a random stranger but an expert in experimental design and performance and data management. Any physical scientist will validate my statements.

No, you are just a random stranger on the internet, to me at least. I am currently unaware of your credentials. You say that you're an expert but offer no proof.

Here is a more knowledgeable resource than an online dictionary:
http://blog.minitab.com/blog/real-w...nt/accuracy-vs-precision-whats-the-difference

And here is the seminal quotation from the above resource:
"Accuracy refers to how close measurements are to the 'true' value, while precision refers to how close measurements are to each other."

From a blog, by a stranger. I still think I'll stick with the definitions provided at the links that I posted. Merriam-Webster and The Oxford English Dictionary both concur with those "internet dictionary" definitions by the way. Merriam-Webster has been at it for over 200 years and Oxford for over 120. If they've been wrong all these years, your time might be better spent convincing them rather than trying to convince me.

 

[rpenmanparker]

No, you are just a random stranger on the internet, to me at least. I am currently unaware of your credentials. You say that you're an expert but offer no proof.

From a blog, by a stranger. I still think I'll stick with the definitions provided at the links that I posted. Merriam-Webster and The Oxford English Dictionary both concur with those "internet dictionary" definitions by the way. Merriam-Webster has been at it for over 200 years and Oxford for over 120. If they've been wrong all these years, your time might be better spent convincing them rather than trying to convince me.

No one is going to fool you. Let it be as you say.

 

[denton]

It is not uncommon for the dictionary definitions of words to be less precise and meaningful than the way that professionals use them. Speed and velocity are often used interchangeably, when to a student of physics they are not the same. Weight and mass are often used incorrectly. In our hobby, people speak of clips when speaking of what most of us call magazines. Sausages and wells have casings. Cartridges have cases.

So you get to decide: Use the definitions the professionals use, or don't.

Since some are hung up on credentials, I have a degree in physics, I'm a professional in the field of industrial experimentation and measurement system qualification. I've been doing that for 20 years, and have done 3 books, 2 of which have chapters dealing with exactly this issue. I'm the author of our company's technical curriculum, and co-author of a major software application in the field.

If you don't believe me, you can access nist.gov, the National Institutes of Standards and Technology web site or you can access the Auto Industry Advisory Group's handbooks on measurement systems analysis, or buy a copy of Dr. Don Wheeler's Evaluating the Measurement Process.

All those sources agree that rpenmanparker's definition is the one that professionals in the field use. Or you can go with the colloquial version. One leads to better communication than the other, but it's not up to me to worry about which someone chooses.

 

[Frank Ettin]

....I still think I'll stick with the definitions provided at the links that I posted. Merriam-Webster and The Oxford English Dictionary both concur with those "internet dictionary" definitions by the way. Merriam-Webster has been at it for over 200 years and Oxford for over 120. If they've been wrong all these years, your time might be better spent convincing them rather than trying to convince me.

The problem with standard dictionaries here is that lexicographers in compiling standard dictionaries consider usage. That's fine when the goal is to define the common meanings of words in ordinary use.

But here we're really discussing technical terms and are interested in their proper, technical usages. So it's more appropriate to look to technical sources.

So, for example, this is what they say at the National Physics Laboratory:

Accuracy is a qualitative term that describes how close the measurements are to the actual (true) value.

Precision describes the spread of these measurements when repeated. A measurement that has high precision has good repeatability.

And from the site Science Notes:

Accuracy

Accuracy is a measure of how close your experimental measurements agree with known values. The closer your measurements are to the known value, the more accurate the measurement....

Precision

Precision is a measure of how close your experimental measurements agree with each other. The closer each measurement is to the other measurements, the more precise your measurement....

The CVs of the writers may be found here.

You might note that the technical definitions from these two sources are consistent with each other.

 

[KansasSasquatch]

Well it seems either the scientific community needs to change (unlikely) or there needs to be an edit to most dictionaries.

 

[Frank Ettin]

Well it seems either the scientific community needs to change (unlikely) or there needs to be an edit to most dictionaries.

Not necessarily. Dictionaries tend to reflect common usage. But common usage is skewed by the fact that many people misuse technical terms.

So, for example, Merrim-Webster on-line defines velocity as:

1a : quickness of motion : speed

b : rapidity of movement

c : speed imparted to something....

That might be how most people routinely use the word, but it's also technically incorrect. In physics velocity is a vector, i. e., it describes both a speed and a direction.

The casual, incorrect use of "velocity" might suffice in many day-to-day situations; but it is in a sense a debasement of the word. It makes it more difficult to communicate technical matters where the difference between speed and velocity are material to understanding a particular concept.

 

[hdwhit]

rpenmanparker wrote:
Why shouldn’t we all want to learn something new to us every day?

I agreed with the desirability of knowing about using the proper terms in the first line that you quoted.

But, as I thought I clearly explained in my post, I can still help someone who brings me two distinctly different targets without needing to enlighten them as to the distinction between the terms.

I'm not talking about semantic games here. I'm not saying that I could call "accuracy", G'nip and "precision", G'nop, and still get to the same place. I am saying that the problem can be fixed without needing to address either "accuracy" or "precision" - concepts which can come later in the conversation - if at all.

After all, if I begin by telling you about the distinction between "accuracy" and "precision" before I start to address the problem you are having, you're probably just going to "check out", have your eyes roll back in your head - a phenomenon you have clearly already observed in the various responses to your original post - and I will end up achieving neither the resolution of your problem nor the enlightening you on the proper usage of the terms.

 

[Frank Ettin]

....if I begin by telling you about the distinction between "accuracy" and "precision" before I start to address the problem you are having, you're probably just going to "check out", have your eyes roll back in your head - a phenomenon you have clearly already observed in the various responses to your original post - and I will end up achieving neither the resolution of your problem nor the enlightening you on the proper usage of the terms.

That's true. Part of understanding words and their meanings is understanding how to use them and how not to use them. A particular concept or idea isn't necessarily a part of every conversation.

 

[Robert]

This horse has been throughly beat.