WEBSITE DEVELOPMENT AND COLLECTION GUIDELINES Early in 1995 I began making available via gopher and then over the WWW some files I had written which summarized basic information about some mathematical topic or other. Usually these were posts or email in response to some questions on one of the math newsgroups. (I've participated in the groups off and on since about 1984, but I haven't saved my comments regularly). The hope was that I could (a) reduce traffic on the newsgroups, (b) avoid having to repeat my own summaries, and (c) sort files in a way which would let me find things later. It was obvious that my own posts were often inferior to others that I saw or received in mail, but I felt a little uneasy making available other people's work, even if it had appeared publicly. Subsequent conversations have convinced me that as a rule this attitude is unnecessarily cautious and even a little silly. Since I had for several years saved these other informational items as I came by them, it wasn't hard to find interesting mathematical essays which could be included. Some of them are now at this site. Over time, I continued to collect more of these items. The process of preparing items for inclusion in the collection (especially of maintaining the index files) was too time-consuming, and so by the Fall of 1997 it was necessary to provide a better presentation of the files. I migrated the files to a set of pages modeled after the Mathematics Subject Classification scheme used by the American Mathematical Society and Zentralblatt fuer Mathematik. Unfortunately I have had to drop the provision of a "master index" -- it has become too unwieldy -- but in exchange the index pages have become more informative, more standardized, and better cross-linked (I hope). During 1998, the index pages were much improved and, I think, became the highlight of this site. Significant efforts were made to make sure the index pages were correct, informative, and of some real assistance in matching visitors with the information desired. A uniform "look" was established, and the index pages brought up to prevailing WWW standards for HTML protocols, stability, and so on. The navigation pages, including several search engines, should make the whole site easier to use. In particular, the "MathMap" images should make it easier to find material whose MSC classification stretches across more than one area. The directory structure was streamlined, and several other background improvements were made to enable future development. The net result is a mixed bag. On the one hand, this site is much too heavily weighted towards my own writing to be thought of as an archive for sci.math.* (use Dejanews for that!), and is biased towards my own interests too much to be anything like an on-line dictionary/encyclopedia of mathematics. On the other hand, there are far too many files by other authors for me to claim it's just a private web site, or solely a personal initiative. I hope the reader can see past the oddness of this mixture and find something useful. There are many web sites devoted to mathematics or portions of mathematics. They tend to cross-link each other, so if, for example, you visit the American Mathematical Society (http://www.ams.org) you will find links to many of these other sites; you can keep clicking away all day finding more links. I see no reason to duplicate these lists of links. Instead, almost all links provided link directly to files which, I hope, convey some mathematical content. Exceptions were made only for sites which are indeed fairly encyclopedic within some subarea of mathematics. (Only a handful of areas have a champion of this type at present.) With so many math sites now available, it is necessary to identify the unique aspects of this site which distinguish it from others. I believe this site is distinctive in three ways: (1) It has a well-defined target audience (background including some undergraduate mathematics, but not active in research in the area under discussion) (2) Links are content-intensive and usually reside at this site. Thus this site offers material unavailable elsewhere except through links to here. (3) Coverage is intended to mirror the mathematical landscape -- not at all uniformly, but a serious attempt is made to put each piece of information in its proper mathematical setting. As implied in the welcome message to this site, this material is intended to provide correct, succinct, and useful answers to questions such as might be asked by undergraduate math majors, grad students, and professionals not working in a specific area. In particular, there is really very little here at a level of calculus or below, and there is very little which is too advanced to show up in some graduate-level course -- actual research continues to be primarily in print journals. Coverage is over a broad sweep of mathematics, but tends to concentrate in algebra/number theory and geometry/topology, with adequate material in combinatorics, numerical mathematics, and logic, too. But there's little analysis, and less applied mathematics and statistics. While I have not made available any files which I know to be incorrect or misleading (at least, not without appending correcting information), there is naturally no guarantee that what you find here is mathematically sound. Please let me know ASAP if you see something in these files which should be updated, corrected, or removed. I accept responsibility for errors in my own writing, of course. The rule of thumb is probably: if there are posts and letters from me in a file, it's because I understand the topic well; these files are probably free from egregious errors. If there are no posts or letters from me in a file, it probably means I found the topic to be interesting enough that I might want to learn more about it. While I think the comments you read in such a file are on-target, this is in some cases merely a novice's opinion. Apart from mathematical correctness, there is reason to be concerned about the quality of the exposition. I will confess that much of what is here is not of presentation quality -- if I had time to sit and rewrite each letter or post I've made, I would try to do a much better job. Still, there is a reasonable chance that some of these files might be helpful to someone, so I feel it is appropriate to set them out as is. Over time, some of these files will probably be rewritten. The website is undergoing steady improvement at this time (Jan 1999) Apart from simple growth, some changes may be brewing in the near future: (1) Text introductions to many of the areas are minimal or of poor quality. I am planning to have guest authors write these. There will be more "maps" on index pages as the procedures for developing them are clarified. (2) Over time, more of the secondary and tertiary areas of math will warrant separate index pages. During the next few years we will migrate toward the MSC2000. (3) Since the division of mathematics into 61 areas and many subareas is quite uneven, it seems reasonable to include more pages which provide orientation to distinctive areas of mathematics not readily given their own page in the MSC. I would be happy to increase the scope of this collection of articles, subject to the good humor of my site administrator. If you have some essays which you think fit the spirit of this collection, let me know. I reserve the right to decline inclusion (it's still my web site!), but I can't see any particular reason to be unwelcoming. Undoubtedly the ideal would be for those of you who have similar collections to provide URLs which I could add to the index pages (you ought to suggest an appropriate classification). This will provide one-stop shopping for those seeking mathematical guidance, without overloading the memory of our system locally. If you have suggestions for how to develop this collection please let me know. Significant effort has been made to make these materials available to those with comparatively primitive machines. Most of the "Selected topics" are usually USENET posts or vanilla email, so they are almost all straight text and should be easily read in any setting. There are a few .tex files and computer programs included, but no .ps, .dvi, .pdf, .midi, ... files. (A few .jpg and .gif images are linked from the HTML files, but are essentially "fluff" and so can be avoided if necessary.) dave ( = rusin@math.niu.edu ) You are reading known-math/collection/policy The collection itself may be accessed through welcome.html Last modified 1999/05/12