Talk:Counting

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Does Wikipedia have an article on things that are counted in a way like this:

1, 2, 3, 4, 5A, 5B...

(Description: Some of the items being counted are designated as a single item with multiple parts designated with letters.) In the real world, I hear that there are a lot of things numbered like this. 66.245.66.35 20:36, 10 Apr 2004 (UTC)

Yes, these are commonly used in outlines as a numbering scheme ... but alas, neither of those articles says anything about it. (Is there a better name for this than "outline numbering" ?). Also, I've seen a few books that, instead of numbering pages from "1" and incrementing all the way to the end, start with "1:1", "1:2", ..., then the first page of chapter 2 resets to "2:1", then "2:2", then "2:3", ... Is there a better name for this than "per-chapter numbering" ?

This is a form of segmented numbering. The page number consists of multiple segments, which are concatenated to define the unique page number. As discussed below, this is enumeration (listing the items), not counting. There is the concept of a "rollup" in business computing which adds up the items in a specific segment. You usually cannot compare the items in distinct rollups (apples versus oranges), which can be in different classes. Ancheta Wis 00:50, 25 Apr 2005 (UTC)

--DavidCary 22:44, 23 Apr 2005 (UTC)

Sorry, this is not counting. This is one-to-many correspondence, which fails the basic idea of 1-to-1 correspondence required for the counting operation in mathematics. The technology for 1-to-many correspondence is a topic in database management systems, where the 5A and 5B referred-to above, have just defined a primary key (PK, which is not a number, its a sequence of symobols, defined for each type) for the things being listed. The good news is that once a PK is defined for a set of the things, you can start to run searches on the set, just like the technology used to operate Wikipedia. Ancheta Wis 00:50, 25 Apr 2005 (UTC) The reason that WP works so well, though, is not the database. It's the SQUIDs which simply save all the existing searches to disk. When an original query is requested, that is what takes up the database search time in WP. Once the item's PK's are saved, the items can be cached to the SQUIDs. Ancheta Wis 00:50, 25 Apr 2005 (UTC)