北京大学：《信息检索》课程PPT课件讲稿（自然语言处理）03 Web Spam

NC&IS Web Spam The CCF Advanced Disciplines Lectures 彭波 pb@net.pku.edu.cn 北京大学信息科学技术学院 6/27/2010

Web Spam The CCF Advanced Disciplines Lectures 彭波 pb@net.pku.edu.cn 北京大学信息科学技术学院 6/27/2010

street spam email spam 25名 05 YOUVE GOT MAIL 直招 收72 92

street spam email spam

What Is Web Spam? Spamming any deliberate action solely in order to boost a web page's position in search engine results,incommensurate with page's real value ■ Spam web pages that are the result of spamming "Page 1...It's what we do." Approximately 10-15%of web pages are spam seo age

What Is Web Spam? ◼ Spamming = any deliberate action solely in order to boost a web page’s position in search engine results, incommensurate with page’s real value ◼ Spam = web pages that are the result of spamming ◼ Approximately 10-15% of web pages are spam

Why Web Spam Is Bad We appreciate your taking the time to help us improve our service for your fellow users around the world.By helping us eliminate spam,you're saving millions of people time,effort and energy. Google

Why Web Spam Is Bad We appreciate your taking the time to help us improve our service for your fellow users around the world. By helping us eliminate spam, you're saving millions of people time, effort and energy

Detecting Web Spam Spam detection:a classification problem "根据特征，判别一个网页/网站是否是spam? But what are the "salient features"? ·通过了解spamming技术来寻找特征 Finding the right features is "alchemy",not science ,Spammers也在不停的改进技术-it's an arms race!

Detecting Web Spam ◼ Spam detection: a classification problem ◼ 根据特征，判别一个网页/网站是否是spam？ ◼ But what are the “salient features”? ◼ 通过了解spamming技术来寻找特征 ◼ Finding the right features is “alchemy”, not science ◼ Spammers也在不停的改进技术 –it’s an arms race!

NC&IS The Spammer's Toolbox

The Spammer’s Toolbox

Techniques Taxonomy term boosting techniques link hiding

Techniques Taxonomy

Techniques Boosting Term how? term body repetition boosting title techniques dumping hiding meta tag weaving anchor stitching url 32 link

Techniques / Boosting / Term

Term Spamming-What? Web Casino Title Our customers agree that we are the best online gambling site! Body URL Anchor text A great online gambling site

Term Spamming-What?

Weaving Remember not only airfare to say the right plane tickets thing in the right place,but far cheap travel more difficult still,to leave hotel rooms unsaid the wrong thing at vacation the tempting moment. Benjamin Franklin US author diplomat,inventor physicist,politician,printer(1706 -1790)

Remember not only to say the right thing in the right place, but far more difficult still, to leave unsaid the wrong thing at the tempting moment. Benjamin Franklin US author, diplomat, inventor, physicist, politician, & printer (1706 - 1790) Weaving Remember not only airfare to say the right plane tickets thing in the right place, but far cheap travel more difficult still, to leave hotel rooms unsaid the wrong thing at vacation the tempting moment. Benjamin Franklin US author, diplomat, inventor, physicist, politician, & printer (1706 - 1790) Remember not only airfare to say the right plane tickets thing in the right place, but far cheap travel more difficult still, to leave hotel rooms unsaid the wrong thing at vacation the tempting moment. Benjamin Franklin US author, diplomat, inventor, physicist, politician, & printer (1706 - 1790)