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#1
06-30-2006, 07:05 PM
 Subway Prophet Guest Join Date: Jun 2006
Stuck on a statistics/probability question...

I think this is primarily a terminology question, so if I get some words wrong, please correct me on that. Oh, and I may not be getting the core concept correctly either. But I'm sure that once I know the word I'm looking for, it'll be easier for me to read up on it. Google helps those who use the right vocabulary.

What is it called, when you collect all possible rolls from a specific group of dice? For example: I'm analyzing the probabilities of rolling all possible numbers from 3 6-sided dice (i.e. 3d6). I see that there is one way of getting a 3 (1 and 1 and 1), 3 ways of getting a 4 (1 and 1 and 2, 1 and 2 and 1, 2 and 1 and 1), and so on. I'm looking at all possible... whatchamacallits? When you're done (and depending upon the number of dice), you can plot the data and get a nice bell-shaped curve.

I think that the word I'm looking for is "permutations", except I had the impression that permutations dealt with possible orderings of a set of items, rather than possible outcomes of a sequence of random events. Perhaps the word I'm looking for is "distribution"? "Histogram" keeps popping up too, but I'm not sure it's appropriate in this context.

Both the Wikipedia entry and the Mathworld entry on dice show diagrams of what I'm looking for, but the language starts to get over my head. I get similar results looking through my old college textbooks from statistics and discrete mathematics.

Oh, I got a B and an A in those classes, repsectively ...but I haven't retained much. :wally
#2
06-30-2006, 07:55 PM
 MikeS Charter Member Join Date: Oct 2001 Location: Williamstown, MA Posts: 3,161
The best word for what you're looking for, really, is "outcomes", but that won't really help you with Google. "Permutations" and "combinations" aren't really what you're looking for, since they involve picking a subset of elements from a certain set, without repeated "choices" allowed (and with and without ordering, respectively.) "Distribution" refers to the set of all possible outcomes, and how likely they are; and a histrogram is just a graph of a (discrete-valued) distribution.

So I'd go for "outcome" and "distribution" when you're out a-Googlin'.
#3
06-30-2006, 09:30 PM
 Thudlow Boink Charter Member Join Date: May 2000 Location: Springfield, IL Posts: 16,736
I agree with MikeS. The word "outcomes" may be a bit more general than what you're looking for, but it does apply, and I can't think of a more specific term (which doesn't necessarily mean there isn't one).
#4
06-30-2006, 11:18 PM
 ultrafilter Guest Join Date: May 2001
You're looking for the distributions of sums of dice. I don't think there's any more specific term for it.
#5
06-30-2006, 11:23 PM
 TJdude825 Guest Join Date: Feb 2000
The term "sample space" comes to mind.
#6
07-01-2006, 11:32 AM
 Thudlow Boink Charter Member Join Date: May 2000 Location: Springfield, IL Posts: 16,736
Quote:
 Originally Posted by TJdude825 The term "sample space" comes to mind.
I got the impression that the OP was asking about what to call the individual outcomes that make up the sample space, but yes, it is worth noting that "sample space" is the collective term for the set of whatchamacallits the OP is talking about.

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