Thursday, November 29, 2007

Search Engine page-ranking algorithms

Most Search Engine page-ranking algorithms rank pages based on the following aspects:

.. Content of the website
.. Representation of content, keywords, and links on websites
.. Location and number of inward and outward links on
websites
.. Relevancy of search terms as compared to the websites
Given below is a brief description of the page-ranking algorithms
of some of the most popular search engines.

Google
You can submit your website to Google at the following URL:www.google.com/addurl.html Submitting your site will only make

Google aware that your page exists; it is quite possible that your pages may get crawled even if you have not submitted. It is advisable to submit the home page and some inside pages. Inside pages are added to the submission, just in case the home page is found too slow to load or crawl. The pages that are submitted should link to the rest of the pages. Google indexes the full text that is visible on any page that it crawls. It generally does not index the metatags – keywords or descriptions.

When Google lists your page in the search results, the description that is displayed is the extract of text that is around the first line where the search word appears on the page. It may thus be a good dea to write a good description of the page and build it around the most likely search term(s) and place that near the top of your page. You should remember that one sure way of getting your site listed and indexed is if there are several links that point to your site and such links appear on web pages that in turn have several other links pointing to them. The term “link popularity” is used for this. It analyzes links of the pages that it has visited and this “link analysis” helps to determine the ranking of the page. Google uses a proprietary PageRank algorithm for determining relevance and ranking of pages in the search results. Location and frequency of the search term on your web page are no doubt factors in ranking; however, off-the-page factors such as link analysis are more important. Generally, Google provides search results based on relevancy, meaning that it returns a list of pages ranked by the number of other web pages linking to each page, as well as other mathematical algorithms

Yahoo!

Yahoo! offers a human-powered directory and offers its results to visitors. The directory is supplemented by a web page index created by crawling. The directory is an important channel in the area of search engine marketing. It is popular and is used extensively by people to locate sources of information. Moreover, the directory is a valuable boost to your site for crawling and ranking in other search engines, as the directory provides a high-quality link to your website. When a visitor is looking for information on relevant sites, she could either browse through the hierarchy of directories and subdirectories or search for an appropriate directory through a search interface. As your site can be listed in just one category, generally, the choice of category is an important step. Choose the top category that your target visitor who is making a search may select out of the different categories offered to him/her. Select your target keywords and find out which categories relate to those keywords. For submission of non-commercial sites, the Yahoo! Express submission is recommended rather than the Standard submission option. - 79 -

The results page in your chosen category will list your site in two possible sections (for most categories). One section is called "Most Popular Sites" and this is on top, while the second section contains the remaining listings in Alphabetical order. Yahoo! does not reveal how it includes certain sites in the “Most Popular Sites” list. However, link analysis and click-throughs are likely to be factors. You cannot pay to be included in this section. Certain sites with sunglasses shown next to their name or an “@” symbol shown at the end of the name reflect that Yahoo! considers those sites to be excellent.

Inktomi (MSN Search, AOL Search, Hotbot)

Inktomi is a search engine that does not offer its search services through its own site, but through Partner sites – prominent ones being MSN Search, AOL Search, HotBot and others. Inktomi, through its crawler, creates three different indexes. “Best of the Web” index has around 110 million pages that it indexes on the web and considers high in link analysis. The next set of around 390 million pages is indexed as “Rest of the Web”, considered as lower in link analysis. The third index is of paid inclusion. It also offers specialized regional indexes as well as targeted news, multimedia and directory indexes. It avoids duplication of the same page in more than one index. Link crawling and paid inclusion are the two most effective ways to get covered by crawling. For bulk submissions to its paid program, it offers IndexConnect (for 1000 or more pages). Again, there is a cost-per-click basis with a monthly minimum. Ranking at Inktomi is determined by a combination of factors including HTML links, keywords and description tags near the top of the page or in the title tag. If the search string matches with what is found at these places on the page, the ranking is higher. Link analysis and analysis of clickthroughs are other important criteria that it adopts.

AltaVista

AltaVista will accept free listings through its “addurl” link, but it also has paid inclusion features. Generally, their crawler may visit every four weeks. Paid inclusion may be desirable if you have a new website or web pages or if you alter your web pages frequently, and you do not wish to wait until the next cycle of crawling. There is an “Express Paid” inclusion service of self-service type for up to 500 pages at a time. This service will enable weekly crawling. Their bulk program called “Trusted Feed” will enable the pages to be directly linked to their index. Pricing for “Trusted Feed” is on a cost-per-click model with a monthly minimum. In this program you can submit the Meta data, descriptions and keywords directly to the index. Nevertheless, the engine will check whether the destination page has the same Meta data or not and could levy a penalty for spam. AltaVista’s ranking policies are a combination of various factors. The frequency and positioning of keywords and descriptions is important, as are title tags or words that appear near the top of the page. AltaVista applies link analysis to determine relevancy and page ranking. It levies penalty on spamming and does not recognize invisible or tiny text, keyword stuffing, identical pages, mirror sites, or quick meta refresh tags. 3.4 Keywords — Optimizing Your Site to Get Top Billing at Search Engines When a user enters a search term, also known as a “keyword”, into a search engine, the engine runs through the billions of pages in the database and awards each one a “relevancy score”. The higher your score, the higher your listing. If your site doesn’t contain the keyword used by the searcher, the only score it’s going to get is a big, fat zero. Your first task then is to make sure you know which keywords are most relevant for each of your sites.

There are three ways to figure out your keywords:


Ask Your Competitors

This is the cheapest way to find many of the most important keywords. Simply log on to a search engine (AltaVista is good, Google is better) and carry out a search for sites like yours. Open the top site, and once the home page has downloaded, click on “View” in your browser, and then “Source”. That will reveal all the HTML used to build the web page, including all the keywords that have been specially inserted. Some of those keywords will be relevant to your site. Others, of course, won’t be relevant and there will be lots of other keywords that aren’t obviously listed, such as “vitamins” for example. You can repeat the process on other sites, using different keywords, and build up a pretty long list.

Ask the Pay-Per-Clicks

Pay-per-click sites actually let you see how popular a keyword is. They’re not being kind; they’re trying to make money. The more webmasters bid on those keywords, the higher the bids are going to rise — and the more money the pay-per-clicks are going to make. FindWhat, for example, has a Keyword Center. Other pay-per-click sites offer similar features. One of the most popular key word discovery tools, however, was provided by former PPC giant Overture.

You can play around with this free keyword selector tool at: www.inventory.overture.com/d/searchinventory/suggestion/ Use a Specialized Tool Not too surprisingly, a number of companies have popped up to supply specific keyword services for a fee. The best of these is WordTracker.com. They’re not bargain basement, but you get what you pay for. They’ll give you all the keywords you need and in my experience, they’re a sound investment. GoogleFight.com is another useful tool to see whether one keyword is more popular than another. The site compares two keywords and tells you which is more popular. It’s free and has a limited use, but it’s fun to play with.

As you make up your list of keywords, bear in mind that it’s also worth looking at key phrases. It’s quite possible that a user looking to buy flowers online might search for “red roses” or “cheap bouquets” as well as just “flowers”. Key phrases are often overlooked by competitors, so you’ve got a pretty good chance of getting a high placement with the right combination. Don’t worry too much about the competition though. Some people will tell you that you’re better off trying to find keywords that no one else has thought of and others will tell you to throw in keywords that are only slightly relevant to your businesses. In my experience, that’s a waste of time. If your competitors are using certain keywords, it’s because they know they work. And if any of your visitors found your site using irrelevant keywords, you're not going to sell them anything. Don’t try to reinvent the wheel here: just try to figure out the most popular keywords and the best key phrases to put on your site.

Whichever of these methods you use — and I tend to use more than one — you should end up with a pretty comprehensive list of keywords that you can stick into your website. The next question then, is how do you use them? When a search engine assigns relevancy to a site, it looks for the keywords in a number of specific areas. Title Tag The title tag is written in the section of the web page and after the


The title tag is usually between 50 and 80 characters including spaces. Different search engines have different limits so you want to make sure that your most important words are near the beginning of the title. The rest of the title is made up of keywords and phrases but in fact, you don’t want to put in too many keywords here. Just place one keyword as the second or third word in the title. Too many, and your site could be seen as spamming. You can also list more keywords in the and sections of the area, but because these areas have been so abused in the past, a number of search engines today will skip right past the title tag and go straight to the web copy.

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