Is There a Mode when All Data Points Occur Equally?
Date: 05/02/2007 at 13:56:34 From: TJ Subject: Is there a "mode" when every number is different? If you have a set of data such as 2, 67, 39, 20, 15, and 56, what would the "mode" be?
Date: 05/02/2007 at 21:06:16 From: Doctor Rick Subject: Re: Is there a Hi, TJ. Take a look at this answer in the Dr. Math Archive: More Than One Mode? http://mathforum.org/library/drmath/view/61375.html At the end you'll see a reference stating that a set in which no element occurs more than once has no mode. You could also argue that, in any set in which all the elements occur the same number of times (including once), every element is a mode. It really doesn't matter. In real life, we wouldn't bother calculating statistical measures for such a small set; those measures are meant to distill a *large* set of numbers into a small set of numbers (mean, median, mode(s), standard deviation, ...) that characterize the distribution. We study small sets like your example in order to see up close how statistical measures work, but we shouldn't focus on these toy examples too much, or on the issues that arise in dealing with them. The larger the set, the less likely it is that every number will appear exactly the same number of times. If the number of occurrences is *nearly* the same for all numbers, then the mode (or modes) is meaningless; what is significant is that the distribution of the data is nearly flat. If each number appears only once, it suggests that you'd get more interesting results by binning the numbers to increase the number of occurrences in each bin. (For instance, total the counts for numbers 1 to 10 in one bin, the counts for 11 to 20 in the next bin, etc.) You may well find that a mode (or modes) will become evident when you do this. Thus there is no point in worrying about what to call the mode when each number appears only once; in practice you won't continue to work with the data in that form. - Doctor Rick, The Math Forum http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.