Accuracy vs. precision

[aarondhgraham]

Do not engage, do not engage, do not engage!

Aarond

.

 

[buck460XVR]

Since spotting this in THR some weeks back, this has become my very most favoritest ever sig line.
Sent it to a professional editor friend, too.

After several years on gun/hunting/motorcycle forums, I have come to the realization that some folks feel the need to show their superior intelligence over the rest of us. Similar to all those "dumb clerk at the LGS" , "idiot at the gunrange" or "stupid salesperson at Wal-Mar" threads. Folks making a spectacle the how much more knowledge and intelligence they have over the average person, especially when they have Google available. Somehow knowing the correct adverb to complete a perfect sentence makes them a better hunter. Somehow knowing what ACP stands for when the girl at Wal-Mart doesn't makes one a Massad Ayoob. Somehow knowing the exact technical term for everything makes you a better and more interesting person than the dummy that still calls it a clip.

Just got back from a 2000 mile round trip cross country motorcycle rally. Good friends from all over the lower 48 met up in the Ozarks of Missouri. There were a lot of different terms used for various things. Sometimes I had to ask just what the other guy meant. Didn't make any of us a better rider or faster in the curves. Just made us who we are. If folks want to be that annoying person no one wants to sit next to every other Saturday night for card club....so be it. Theiyr're welcome to sit next to me.


Just sayin'........

 

[MEHavey]

Precision is putting all your bullets in one hole.
Accuracy is having that hole where you want it.

I now return control of your web site to less mundane things

 

[Frank Ettin]

Geez
What happened to reading Webster’s Dictionary

It's okay as long as one uses it properly.

1. Accuracy, Merriam Webster On-linel:

   1 : freedom from mistake or error :
   

   CORRECTNESSchecked the novel for historical accuracy​

   
   2 a: conformity to truth or to a standard or model :
   

   EXACTNESSimpossible to determine with accuracy the number of casualties​

   
   

   b: degree of conformity of a measure to a standard or a true value— compare PRECISION entry 1 sense 2a​

   
   
2. Precision, Merriam Webster On-line:

   1 : the quality or state of being precise : EXACTNESS
   
   2 a: the degree of refinement with which an operation is performed or a measurement stated
   — compare ACCURACY sense 2b...

 

[Walkalong]

Precision is putting all your bullets in one hole.
Accuracy is having that hole where you want it.

I now return control of your web site to less mundane things

I like both of these. So the way I have always looked at it, posted earlier, is wrong.

MCB & Denton have stated it correctly. Maybe I can remember in the future.

 

[Pete D.]

Nice explanation. When I shoot 1,000 yard bench rest, I need precision and accuracy, but in 100 yard bench rest it depends on whether you are shooing Group or Score. You can have a great score with a mediocre group or a tight group with a poor score as the group is in the wrong place.

Bob

Yep. That happened to me in a muzzleloader 100 yard match. I shot a very nice group the size of a quarter. It was off, though, a tad to the right. The winner shot a larger but more centered group.

 

[MEHavey]

FO to TOC:
Five Rounds, Fire for effect

( Boom. B-B-Boom, Boom.....)
(delay)
( Whump-WWhump, WWhump )

FO to TOC:
Great Precision.
All five rounds within 50 yards each other.
1.5 seconds total impact span.

TOC to FO:
So we're good ?

FO to TOC;
Right in the CG's backyard/OWC Spring garden party
Yeah. I think you're done

 

[murf]

when you measure the same part repeatedly with the same device.

sounds like you are banging your head against a wall.

If you get a tight group you’re looking at precision.

precision has nothing to do with the amount of dispersion from the mean only that all members of the group are dispersed the same.

fires four shots and gets them all within the the second smallest ring but none of them are close to each other

the group may still be precise if each shot is the same distance from the mean.

that tight group is far from where you aimed

that would require a sight adjustment, or kentucky windage.

The new shooter probably thinks he’s looking at poor accuracy when in reality he is looking at

sight adjustment

ake accuracy every time.

agreed, precision has no place here. the goal in shooting is, for each shot, to make poi (point of impact) minus poa (point of aim) the smallest distance you can make it. that is accuracy and that is all i am concerned about.

murf

 

[Craig_AR]

You can evaluate accuracy for a single shot.
To evaluate precision you must have multiple shots.
(STEM definitions)

 

[Kleanbore]

the group may still be precise if each shot is the same distance from the mean.

You are going to have to explain that one.

 

[murf]

google it: https://www.gcse.com/science/precision.htm

murf

 

[Kleanbore]

google it: https://www.gcse.com/science/precision.htm

That is correct, and it contradicts what you said before.

 

[MEHavey]

precision has nothing to do with the amount of dispersion from the mean only that all members of the group are dispersed the same.

which is NOT the same as the Google answer:
>
> Precise measurements are ones in which there is very little spread about the mean value
>

 

[Craig_AR]

which is NOT the same as the Google answer

Neither Google nor Wikipedia are anything close to being authoritative, much less accurate. Both show you what dang near anyone has posted on the web, whether they know what they are taking about, or not.
That said, each can sometimes be useful in tracking down legitimately authoritative sources.

 

[LiveLife]

You can evaluate accuracy for a single shot.
To evaluate precision you must have multiple shots.

I like this approach.

 

[murf]

there is very little spread about the mean value

no, just so the spread is the same.

murf

 

[murf]

That is correct, and it contradicts what you said before.

you will have to explain that one.

murf

 

[Kleanbore]

you will have to explain that one.

Not worth the effort. Your understanding is not adequate.

 

[JFrank]

Sanitized
This thread is just getting good

 

[murf]

Not worth the effort. Your understanding is not adequate.

your post was not worth the effort either, but i'm trying to inform others.

murf

 

[Kleanbore]

Murf, you have said

precision has nothing to do with the amount of dispersion from the mean only that all members of the group are dispersed the same.

And you have posted

"Precise measurements are ones in which there is very little spread about the mean value"

Which is it?

 

[Jim Watson]

I understand the gunboard distinction between accuracy and precision.
It amuses me that Precision Rifle competition usually calls for ringing steel plates with one shot each. There is no measure of dispersion, just hit or miss. So does that mean they should call it Accurate Rifle shooting?

 

[Walkalong]

They are shooting precision rifles accurately?

Precision: 5 shots for group size in a specified area


Accuracy: One shot for affect

 

[Dudedog]

Walkalong,
That doesn't look like your .458.
I always thought..45 cal something was the minimum for flies

I can almost see the thought process,
Ha, I am gonna get that sucker, he deserves to die...the only good fly is a dead fly

So I wonder if it would be easier to hit them with a smaller dia but more accurate bullet, or easier with a larger dia but slightly less accurate bullet?

Managed to get one at the range one day, 9mm carbine, as soon as I got him about 30 of his buddies showed up and attacked me....
(took 3 tries but he kept coming back to give me another chance so I just had to keep trying)

 

[murf]

Murf, you have said



And you have posted

"Precise measurements are ones in which there is very little spread about the mean value"

Which is it?

both. maybe you will understand this concept with time. keep trying, kleanbore.

murf