What Search Engine ‘Spiders’ Are And How They Work
Sometimes referred to as ‘spiders’ or crawlers, automated search engine robots seek out web pages for the user. Just how do they accomplish this and is this of importance? What is the real purpose of these robots?
These spiders actually have a rather limited scope of understanding and power available to them, far less than you would think considering they’re minions of such great and mighty names as Google and Yahoo. There’s a lot of things out of the scope of their understanding, such as frames, visuals such as movies or pictures, and scripting via java. Nor can they peek into parts of sites protected by passwords, or click buttons. Well, that’s what they can’t do. What CAN they do?
The ‘submit url’ function places the url into a list of urls the robots are going to explore. Even without submitting your url directly, robots will try to find your site by following links. That’s why building visibility through a web of links is important.
By collecting and following links, robots manage tn transport themselves all over the internet. Think of it as an internet equivalent of the roads we use in our lives. Robots travel on the roads and read the signposts so they know what leads to where.
To ensure that searchers get the right results with the most relevant response to their query, quick calculations are done to see that this happens. Server logs and log statistics program results can be checked by the user to see what pages have been visited and how often. Some robots may be easy to identify such as Google’s ‘Googlebot’, while less well-known ones such as Inktomi’s ‘Slurp’ are not easily identifiable. Some robots even appear to be human-powered browsers.
There may be robots that you do not want to visit your website such as aggressive bandwidth grabbing robots and others. The ability to identify individual robots and the number of their visits is useful. Information on the undesirable robots is helpful also. IP names and addresses of search engine robots are listed at the end of this article in a resources section. These robots read the pages on your website by visiting your page and looking at the text that is visible on the page, and then looks at the source code tags such as title tags, meta tags and others. They look at the hyperlinks on your page. From these links, the search engine robot can determine what your page is about. Each search engine has its own algorithm to determine what is important. Information is indexed and delivered to the search engine’s database according to how the robot has been set up through the search engine.
If you’re interested in seeing which pages the spiders have visited on your website, you can check your server logs or the results from your log statistics. From this information you’ll know which spiders have visited, where they went, when they came, and which pages they crawl most often. Some are easy to identify, such as Google’s ‘Googlebot,’ while others are harder: ‘Slurp’ from Inktomi, for example. In addition to identifying which spiders visit, you can also find if any spiders are draining your bandwidth so that you can block them from your site. The internet has plenty of information on identifying these bad bots. There are also certain things can prevent good spiders from crawling your site, such as the site being down or huge amounts of traffic. This can prevent your site from being re-indexed, though most spiders will eventually come by again to try re-accessing the page.
Justin Harrison is an internationally recognised Internet Marketing expert who provides world class Search Engine Optimization to website owners. For more information visit: http://www.seorankings.co.za
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