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Patent analysis: how search engines deal with
inbound links
This month, Yahoo was granted a patent that
describes how link texts may be used to increase the relevancy
ranking of a web page. Although the patent was filed in 2002,
it provides interesting details about how search engines
can use link texts.
Why are link texts important?
All major search engines pay close attention to the text
that is used in links pointing to web pages. A web page
might be considered more relevant to a search term if the
search term not only appears on the web page but is also
used in the text of the link that points to the page.
Web pages can even get high rankings for a search term
if they don't contain that search term. It's enough that
many websites link to the page with the search term in
the link text. This has been demonstrated with several Google
bombs.
How do search engines treat link texts?
While it is clear that link texts are very important for
search engines, it's not clear how much weight search engines
assign to a link text when they index a page. Are some
link texts more important than others?
The patent indicates that link texts are broken into parts,
called tokens:
Once an anchortext phrase is identified, it is converted
into a set of tokens. For example, page 306 contains
the phrase "best Louis Armstrong site" pointing to
page 200. The tokenization produces the following tokens:
- "Best
Louis Armstrong site"
- "Louis Armstrong"
- "Louis"
- "Armstrong"
- "Best"
- "Best Louis"
- "Best Armstrong"
- "Best site"
The search engine algorithm calculates a weight for each
of these tokens. If the weight exceeds a threshold, the
linked web page may be indexed under that token.
How do search engines calculate the weight?
Search engines consider how often each word or word sequence
can be found in link texts pointing to a particular page
and how often the token appears in the index.
Search engines might assign the greatest importance to
words that appear the least frequently in the search index.
The reason for that is that those words are often more
specifically related to the searched topic.
In addition, a token that appears very often in link texts
that point to a special web page could be given higher
weight. Tokens that appear very frequently in the search
index ("site" or "best") might be discounted because they
are not relevant to the special topic.
What does this mean to your website?
All major search engines use this method to rank web pages.
If you want to get high rankings on search engines, you
must make sure that your web site has good inbound links
with the right link texts.
Optimized web pages are important to tell search engines
that your website is relevant to your keywords. Good inbound
links with the right link texts will enforce the relevancy
of your pages for your keywords.
What you have to do to get high rankings on Yahoo
and Google
- Optimize your web pages for your keywords. While it
is possible to get high rankings for a keyword if you
have enough inbound links that contain that keyword,
it is much
easier to get high rankings for a special keyword
if your web page has been optimized for that keyword.
- Try to get as many inbound links as possible. The links
to your website should use your targeted keywords in
the link text. Do not use the exactly same text over
and over. Vary your link texts and use related but different
expressions for the links to your site.
IBP's link
builder can help you to get targeted links from related
websites, Internet directories and blogs.
The Yahoo patent confirms the methods that modern search
engines use to rank web pages. If you follow the tips and
tricks above, your website will get the best possible rankings
on Yahoo, Google and other major search engines.
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