Exact and precise?

September 10, 2008 9:44 AM

Why do people use the phrase "exact and precise"? What does it mean?

I've heard this phrase a few times and it always seemed very redundant. Is there some context in which "exact" and "precise" don't mean the same thing? Does the phrase come from somewhere - a well-known quote, for example?

posted by Awkward Philip to writing & language (13 comments total)

It could be akin to the distinction between accuracy and precision.
posted by jedicus at 9:51 AM on September 10, 2008 [1 favorite has favorites]

I have not heard this phrase often, but googling shows that it's apparently used a lot. It sounds redundant to me; I don't believe that exact and precise have significant differences to warrant their use together there.

However, precision and accuracy are taught to have different meanings in a science and statistical context; accuracy is the degree of correctness of an observation, whereas precision is the degree of reliability of an observation. Here's a good Wikipedia article on the distinction.

When I do on occasion hear the phrase "exact and precise," I chalk its use up to a confused memory people might have of a science class where they were taught this specialized meaning of precision and to the sense they may have that redundancy might function as an emphatic device.
posted by koeselitz at 9:59 AM on September 10, 2008

I see jedicus beat me to it.
posted by koeselitz at 10:00 AM on September 10, 2008

This sounds like a bit of jargon. Jargons often contain terms that seem redundant to laymen, but there is often a subtle difference between the terms being repeated (e.g. "cease and desist").
posted by kindall at 10:02 AM on September 10, 2008

kind of fun - it IS redundant, as are many common phrases in english ("cease and desist", "each and every", "aid and abet", "always and forever", "hopes and aspirations", "last will and testament", "null and void", "over and above " etc).

I was once told that this actually stems from the norman invasion of england around 1050 AD. Official government communications and documents had to be bilingual so you'd get phrases in the form of "[norman] and [english]". This is supposition on my part, but I would think that after the norman word became familiar, the phrases began sounding redundant - which was then sort of 'ingrained' as a way of stressing important parts.
posted by nihlton at 10:48 AM on September 10, 2008

Oh for god's sake. Can we put that Norman/English thing to rest? There's so little truth to it it might as well be an urban legend, not to mention that it's completely irrelevant here.

And it is not redundant. If you'd bother visiting the Wikipedia article linked above, you'd find:

The results of calculations or a measurement can be accurate but not precise; precise but not accurate; neither; or both. A measurement system or computational method is called valid if it is both accurate and precise.
posted by languagehat at 10:53 AM on September 10, 2008 [1 favorite has favorites]

never mind, seems like the above is likely not true: http://wordoriginsorg.yuku.com/topic/9723/t/Doublets-in-legalese.html

but here are a few more cause they're fun

law and order, acknowledge and confess, help and succor, lord and master, love and cherish, ways and means
posted by nihlton at 10:54 AM on September 10, 2008

Mr Hat - he isn't asking about accurate vs precise. he's asking about exact vs precise which seem more synonymous than the former pair.
posted by nihlton at 10:57 AM on September 10, 2008 [2 favorites has favorites]

from: http://sasalog.com/words-wordplay/69-words-wordplay-74458.html

"They are very similar in meaning and the only difference is the width or scope implied by each word.

Precise tends to indicate a very narrow subject such as at that precise point the whistle blew.

Exact tends to be a little more broad and sometimes cover more than one thing."
posted by nihlton at 10:59 AM on September 10, 2008

Whoa, sorry, you're right—complete brain spasm on my part.

The pairs thing is still a complete derail, though.
posted by languagehat at 11:01 AM on September 10, 2008

nihlton: Mr Hat - he isn't asking about accurate vs precise. he's asking about exact vs precise which seem more synonymous than the former pair.

Yeah, but you did make the Norman argument, and it seems useful to point out that most of the 'redundant' phrases you list aren't examples of redundancy.

"cease and desist" - I sure wish I had an OED here. I'm willing to bet a whole pile of money this one isn't really redundant, and that "cease" and "desist" had, at least at one time, specific legal meanings.

"each and every" - Not redundant. "Each" refers to specific individualities and points up their separate oneness while referring to a common aspect; "every" points instead directly at that common aspect. "I went to each house" and "I went to every house" do not mean the same thing, although they must both be true if one is true; that shade of difference is what makes the phrase "each and every" interesting.

"aid and abet" - Not redundant. See also Bouvier's Law Dictionary, 1856:

TO ABET, crim. law. To encourage or set another on to commit a crime. This word is always taken in a bad sense. To abet another to commit a murder, is to command, procure, or counsel him to commit it.

Encouraging is clearly something different from "aiding."

"always and forever" is redundant, but it's also a ridiculous song, so it doesn't really count.

"hopes and aspirations"- Not redundant. Hopes are things you look to happen with some urgency; aspirations involve some personal agency as things you'd like to do or become.

"last will and testament"- Not redundant. Wikipedia, for instance: "In the strictest sense, a "will" is a general term, while "testament" applies only to dispositions of personal property (this distinction is seldom observed)."

"null and void"- Not redundant. Again, Bouvier's Law Dictionary, 1856:

NULL. Properly, that which does not exist; that which is not in the nature of things. In a figurative sense it signifies that which has no more effect than if it did not exist.
...
VOID, contracts, practice. That which has no force or effect.

"...law and order, acknowledge and confess, help and succor, lord and master, love and cherish, ways and means..."- None of these are redundant.

kindall has it. They're 'jargon;' they sound redundant, but are used because they have different meanings in precise senses.

However, I've never heard of a precise sense for "exact and precise."
posted by koeselitz at 11:46 AM on September 10, 2008

I think the science and stats argument is a red herring.

The bible for this is the International Vocabulary of Basic and General Terms in Metrology (commonly known as the VIM, ISO Guide 99). It defines accuracy and precision as above, but exact (or exactitude) are not used in the VIM. 'Exact' doesn't appear in the standard at all. US-specific documents (as used by NIST, for example) are similar.

'Exact and precise' is not a statement of statistical or measurement quality, at least not one in standard use---'Accurate and precise' would be.
posted by bonehead at 12:47 PM on September 10, 2008

"cease and desist" - ... I'm willing to bet a whole pile of money ... that "cease" and "desist" had, at least at one time, specific legal meanings.

Yes, they're different. Cease means stop. Desist means refrain from doing. So cease and desist means stop what you're doing and don't do it again.
posted by robcorr at 6:03 AM on September 11, 2008