How Search Engines Rank Webpages

Search for anything using your favorite search engine. Nearly instantly, the search engine will sort through the millions of pages it knows about and present you with ones that match your topic. The matches will even be ranked, so that the most relevant ones come first.

Of course, the search engines don't always get it right. Non-relevant pages make it through, and sometimes it may take a little more digging to find what you are looking for. But, by and large, search engines do an amazing job.

As WebCrawler founder Brian Pinkerton puts it, "Imagine walking up to a librarian and saying, 'travel.' They're going to look at you with a blank face."

Unlike a librarian, search engines don't have the ability to ask a few questions to focus the search. They also can't rely on judgment and past experience to rank Webpages, in the way humans can. Intelligent agents are moving in this direction, but there's a long way to go.

So how do search engines go about determining relevancy? They follow a set of rules, with the main rules involving the location and frequency of keywords on a Webpage. Call it the location/frequency method, for short.

Location, Location, Location . . . and Frequency

Remember the librarian mentioned above? They need to find books to match your request of "travel," so it makes sense that they first look at books with travel in the title. Search engines operate the same way. Pages with keywords appearing in the title are assumed to be more relevant than others to the topic.

Search engines will also check to see if the keywords appear near the top of a Webpage, such as in the headline or in the first few paragraphs of text. They assume that any page relevant to the topic will mention those words right from the beginning.

Frequency is the other major factor in how search engines determine relevancy. A search engine will analyze how often keywords appear in relation to other words in a Webpage. Those with a higher frequency are often deemed more relevant than other Webpages.

Spice in the Recipe

Now it's time to qualify the location/frequency method described above. All the major search engines follow it to some degree, in the same way cooks may follow a standard chili recipe. But cooks like to add their own secret ingredients. In the same way, search engines add spice to the location/frequency method. Nobody does it exactly the same, which is one reason why the same search on different search engines produces different results.

To begin with, some search engines index more Webpages than others. Some search engines also index Webpages more often than others. The result is that no search engine has the exact same collection of Webpages to search through.

Search engines may also give Webpages a "boost" for certain reasons. For example, Excite uses link popularity as part of its ranking method. It can tell which of the pages in its index have a lot of links pointing at them. These pages are given a slight boost during ranking, since a page with many links to it is probably well-regarded on the Internet.

Some hybrid search engines, those with associated directories, may give a relevancy boost to sites they've reviewed. The logic is that if the site was good enough to earn a review, chances are it's more relevant than an unreviewed site.

Metatags are what many Web designers mistakenly assume are the "secret" to propelling their Webpages to the top of the rankings. HotBot and Infoseek do give a slight boost to pages with keywords in their metatags. But Lycos doesn't read them at all, and there are plenty of examples where pages without metatags still get highly ranked. They can be part of the recipe, but they are not necessarily the secret ingredient.

Search engines may also penalize pages or exclude them from the index if they detect search engine "spamming." An example is when a word is repeated hundreds of times on a page to increase the frequency and propel the page higher in the listings. Search engines watch for common spamming methods in a variety of ways, not the least by following up on complaints.

About High Search Engine Results

First, high search engine results depend on numerous factors, some of which are outlined above. Other factors include:

• How competitive your industry is online and in your region (Real Estate, Careers, etc.)
• How many other Websites are linked to your Website (the more linked, the higher your site is in the results)
• What keywords the user is searching on
• What text-based content is on your Website and where it is located
• How your Website is submitted
• How often your Website is submitted
• How to use special code (metatags) properly
• How not to be avoided by the search engines as a spammer (such as repeating words too often on your Website or using the same text color as your page color to get you higher in the results)

Secondly, high search engine results are 50% skill and 50% dumb luck. No one can guarantee that you can be in the top 10 to 20 results of a search engine.