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I heard someone use the word 'permutation' for variances in data values, they used the word incorrectly.

What is an acceptable database term for variations in data?

i.e. a phone number can come in as 877-555-1212 or (877) 555-1212 or 877.555.1212 etc.

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  • Are you also thinking of things like "123 N. Main St." vs "123 North Main Street" vs "123 N Main St"?
    – JeffSahol
    Commented Nov 18, 2011 at 20:20
  • If calling these permutations is wrong, then so is calling them variances in data values.
    – John Y
    Commented Nov 18, 2011 at 23:50
  • @JohnY seems to be the definition I find, "The fact or quality of being different, divergent, or inconsistent" thanks for your input though...
    – Chris
    Commented Nov 21, 2011 at 21:59
  • @Chris: You miss my point entirely. Permutations has a special meaning in mathematics, apart from common English usage. So does variance. When you heard someone say permutation to refer to the above example, that is a perfectly acceptable way to use the word, because they are using it in its general English sense. If you are holding them to the mathematical definition of permutation, then why should we not hold you to the mathematical definition of variance?
    – John Y
    Commented Nov 21, 2011 at 22:14

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I'd use the word "format". Note that the numbers are the same just formatted differently. It's already used that way in a number of applications, e.g. excel's cell format.

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    It's not sexy, but this is the term I use as an admin. When you also factor in (at least in the .Net world) that you produce these different combinations with String.Format, it's reinforced.
    – Chris B. Behrens
    Commented Nov 18, 2011 at 19:54
  • for the lack of a better 'data centric' answer (I initially mis-asked this question with the word 'mathematical' instead of 'database' which lead to some of the good 'mathematical' answers.) I thought of 'format' also but agree that it's not a very 'sexy' buzzword.
    – Chris
    Commented Nov 18, 2011 at 21:33
  • How about "anthropocentric presentation format"? ;-) You might want to google "FD:OCA" - for support for using "format".
    – Wudang
    Commented Nov 19, 2011 at 13:24
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In mathematics, "permutation" is a technical term for ... excuse me if I don't have a technically correct definition here, but the concept is: the set of possible subsets of a given size in which order is important, or to put it another way, a mapping from an aribtrary set to a set of ordinals. But in common English, "permutation" simply means "variations" or "alternatives". Like, people will say things like, "What permuations of size and color will we produce of this piece of furniture?"

Note that it's not at all unusual for words to have a technical meaning in a specific context that is different from their general meaning. When a physicist talks about "work" and "energy" he means something far more specific than the ordinary uses of those words, etc.

As to your specific example, I don't know of a single word for that concept. Generally someone would refer to them as "alternative formats" or similar phrasing, as in, "Our computer system supports several formats for phone numbers."

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    A permutation is a particular ordering of the members of a set: so the set [1,2,3] has 6 permutations, including 1,2,3, 3,2,1 and 1,3,2.
    – Hellion
    Commented Nov 18, 2011 at 22:45
  • @Hellion: That's pretty much what I was trying to say, except that it can also be a subset, you can talk about a "permutation of 3 things to 2 things", so the set (1,2,3) has 6 permuations to 2 things: ((1,2), (1,3), (2,1), (2,3), (3,1), (3,2)). I was taught the verbage as "permutation of x things to y things", maybe there's a more technical wording.
    – Jay
    Commented Nov 18, 2011 at 23:03
  • @Jay: I think you're digging yourself further into the hole, regarding mathematics. I have upvoted your answer, because I think it is worth noting that in ordinary English, permutation doesn't necessarily mean what it means in math. But your comment to Hellion was... not valuable.
    – John Y
    Commented Nov 18, 2011 at 23:48
  • To me (and, I think, to mathematics in general, and wikipedia mostly agrees with me), a selection of X things out of Y things (where Y > X) is a combination. (A combination is unordered, but you can then select permutations of the combinations.)
    – Hellion
    Commented Nov 18, 2011 at 23:51
  • But anyway, my goal with the comment was to give you a clearer and more concise way of saying what you were trying to say. :-)
    – Hellion
    Commented Nov 18, 2011 at 23:52
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Back when I tought math, I would call this a "notational ambiguity."

I agree that permutation does not fit well; this term suggests to me the difference between 877-555-1122 and 877-555-1212, as opposed to the differences in your examples.

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I cannot find a cite or supporting quote, but I seem to recall "alternative representations" being used for this.

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