反向链接的信誉和网站排名的关系

在寻找反向链接时应该注意，反向链接质量的高低和内容相关性， 影响反向链接的信誉， 并最终影响网站排名。

首先要看看对方页面本身质量如何，受以下因素影响：

1, 链入和链出的链接以及它们的关系。
2, 是否是特定主题的权威网页
3, 网页级别
4, 是否已经加入主要目录， 如DMOZ等。

然后看相关性。对方页面和自己页面的相关性越强越好，搜索引擎是怎么判断的？搜索引擎看对方页面的文字和你的页面的相关性。对方页面那么多文字，搜索引擎重点看哪里的文字？三个地方 - title文字,H文字和你的链接文字。这些文字叫做reputation keyphrase, 各有各的作用域，详见英文原文。title文字的权重大于H文字，H文字的权重大于链接文字。

在搜索引擎为你的关键词排名时，对方页面的reputation keyphrase文字对其作用域内指向你的链接起作用。被搜索的关键词和这个reputation keyphrase文字相关性越强越好。

评价相关性的时候首先当然要看被搜索的关键词在reputation keyphrase文字中存在不存在，如果存在再看被搜索的关键词在reputation keyphrase文字中的密度和位置。密度越高越好，位置越靠前越好。

总之，在考察对方页面的相关性的时候，重点看对方页面的title文字,H1文字中的关键词，这些关键词最好就是你的页面的关键词，这些关键词重复次数越多越好，这些关键词越靠前越好。至于你的链接文字，则完全在你的掌握之中，毫无疑问要放上你的页面的关键词。

英文原文：

Link Reputation and Your Website

-Understanding its benefits to search engine optimization

by Michael Marshall
Jan 07, 2004

Definition of link reputation

Understanding Link Reputation is extremely important for any webmaster or others concerned with search engine ranking. It involves the relationship backlinks (links pointing back to you) have to a target web page and the context of those backlinks. This relationship and context can be measured with respect to a particular search query or theme and has the consequence of revealing how highly a backlink speaks about your web page with regard to that theme. If link popularity is how many pages talk about you, link reputation is how well backlinks talk about you - quality vs. quantity.

Search engines evaluate link reputation differently putting varying weight on different factors:

Inbound and outbound link relationships
Whether a page is considered an expert page for the theme
Page rank
Whether pages are affiliated to each other (based on IP address and/or domain name
Whether a page appears in a directory listing, like DMOZ.

Importance of link reputation

AltaVista, AOL, Google, HotBot, Inktomi, MSN, Teoma and Yahoo! all use link reputation as a major factor in ranking web pages. What backlinks say about a target page and how well they say it can increase or decrease the relevancy of that page to a specific search query or theme in the eyes of a search engine. Therefore, it has a direct influence on your ranking and, consequently, on the amount of traffic to that target page.

Context of a backlink

The context of a backlink is very important and includes, but may not be limited to, the link text between the open and close anchor tags of the backlink, title text of the backlink page, and instances of header text on the backlink page.

link text - <a href=". . .">LINK TEXT</a>
title text - <title>TITLE TEXT</title>
header text - <h1>HEADER TEXT</h1>

These important context elements are said to qualify the links on a page and are often called keyphrases - not to be confused with this term's standard SEO industry use as a phrase which forms (part of) a search engine query. To avoid this confusion, I will refer to this non-standard use as reputation keyphrase. They determine the semantic, or thematic, sphere of influence of the backlinks they govern. Title text governs all links on a page. Header text governs all links until the next heading of the same or greater importance. Link text only governs the URL with which it is associated.

Consider the following snippet of HTML pseudo-code with three links and accompanying context, reputation keyphrases, marked as RKP:

<title> Title of the page </title> - RKP1
<h1> Header 1 <h1> - RKP2
.
blah blah blah <a href=" URL1 "> Link Text1 </a> blah blah blah
( Where "URL1" Link Text1 marks RKP3 )

<h2> Header 2 <h2> - RKP4
.
blah blah blah <a href=" URL2 "> Link Text2 </a> blah blah blah
( Where "URL2" Link Text2 marks RKP5 )

<h1> Header 3 <h1> - RKP6
.
blah blah blah <a href=" URL3 ">Link Text3</a> blah blah blah
( Where "URL3" Link Text3 marks RKP7 )

In the above example, the following qualification relationships hold:

RKP1 qualifies URL1, URL2 and URL3
RKP2 qualifies URL1 and URL2
RKP3 qualifies URL1
RKP4 qualifies URL2
RKP5 qualifies URL2
RKP6 qualifies URL3
RKP7 qualifies URL3

The strength of reputation keyphrases is also considered. The typical factors considered are the density of the SEO keyphrase within a reputation keyphrase, offset of the SEO keyphrase within a reputation keyphrase, and how many terms within the SEO keyphrase appear in a reputation keyphrase. Furthermore, when calculating the context of backlinks, title text is weighted more heavily than header text which is weighted more heavily than link text.