Help! I can't find anything

YOU'VE got your Mac or PC, a spanking new modem, and your ticket to the world of the Internet via a subscription from one of Ireland's many Internet service providers (ISPs). You've experienced the excitement of that initial "connecting" message - you're in! And you've probably done your first few walk around the World Wide Web through the "hypertext links" (text that you click on that takes you immediately to another Web site) that your ISP maintains on its own site

But then, like hundreds of thousands of others, you have probably become increasingly exasperated. Not because of the widely-publicised connection delays which have given the World Wide Web the nickname of the World Wide Wait. That can be annoying enough, and often greatly reduced by purchasing a little extra memory (RAM, or random access memory, which is relatively inexpensive) and if possible, starting with a modem with a transfer rate of at least 28.8 bits per second (a bit is the basic data unit understood by a computer). But the problem is more fundamental: it's just simply that you don't know where to go.

The single most common problem for newcomers to the Web - and quite a few old hands who are too embarrassed to admit it - is, "But I can't find anything!". There are good reasons why over 30 million of them. That's how many Web pages exist today, and they're breeding fast. To put that in perspective, imagine giving everyone in Ireland a Web page - then multiply by nine. It's hard to fathom now that in June of 1993 there were exactly 130 sites.

By early 1994, a few enterprising souls - mostly American college boys with unassailable geek credentials - realised some sort of roadmap needed to be developed. Up to that point the only way to manoeuvre around the Web was to follow links from site to site or to know an exact Web address (also known as a URL, or uniform resource locator). Then came Yahoo and a variety of other "search engines" and catalogues of the Internet.

A search engine is as any programme that locates information in a database, but increasingly the term is used only for Web-based services such as AltaVista, Infoseek and Lycos.

Slowly fading into obscurity are the text-based search facilities which enabled Internet users to hunt down and transfer files before the advent of the Web's "graphical user interface" (GUI), which is what enables people to see specially designed "pages" with text and graphics. Initially, tools like Archie, gopher (developed at the University of Minnesota and named for the school mascot) and FTP (file transfer protocol) helped searchers burrow through the Net after files.

For example, you might be interested in comets. Using a search facility such as Archie, you track down a file about the formation of comets contained in a university computer in New York, Singapore or Cork. You could then use FTP to go to that computer and transfer that file into your computer. But increasingly, those tiles are available at a single mouse-click from a Web page.

How do search engines work? Basically they send out "spiders" software agents which crawl around the Web gathering information on all its publicly accessible pages. How that data is categorised and then made searchable is initially what differentiated the various engines. There are still basically two main types: search engines proper, which try to index everything, and "subject guides", which are similar to the subject index catalogue of a library.

These guide sites, such as the well-known Yahoo, are selective in the items they "stock". A given library has a defined number of books, with new titles coming in all the time, but it doesn't contain every text known to humankind. Likewise, a subject guide has a staff to filter Web pages for you. They decide which sites have useful content under a given subject, then they catalogue them. So you get fewer results when you go hunting for sites, but much of the chaff has already been discarded for you.

All search engine sites appear to the user in the same way. There's a blank "form" into which you can type one or more search terms, or "keywords". Then you click on a button which usually says "go" or "search". Within seconds, the engine will scan its huge database and return "matches" to your terms.

These are usually listed in the order of how closely a given Web page matches your search terms. Sometimes search engine sites even give the percentage of the match, or they might colour-code the matches - those marked by a red dot are very close, those with a yellow dot have some element of your terms, those with blue are distant matches.

The technology behind the engines is mind-boggling. For instance, when you put a query to the AltaVista search engine maintained by Digital Equipment's research labs in California, the average response time is 0.7 seconds. In that tiny blip of time, your electronic request has travelled halfway around the world and been received by the AltaVista "server" (a powerful computer that stores and disseminates information or programmes). This machine then runs a scan through the 30 million pages it keeps in its index almost all the Web pages in existence - matches your terms to its index, categorises the results, and sends them back to your computer, where they pop up on the screen.

As you can imagine, on a large search engine like AltaVista, there's plenty of scope for matching your terms. Type in the word multimedia" and it returns over 900,000 matches.

Therefore, it's useful to learn some tricks for narrowing responses to your queries so they more precisely match what you are actually trying to find out. You'll also want to investigate the various search sites and see what they can do for you - you'll probably decide on a couple of favourites. This series in coming weeks will cover these and other search engine topics.

Next week: particular search engine sites.