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Introduction to semantic search engine. Tiwei Chen Spring 2009. Keyword Search Engine. We are able to combine the information from different web resources, even if they use different terminologies and languages. Keyword Search Engine.
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Introduction to semantic search engine Tiwei Chen Spring 2009
Keyword Search Engine • We are able to combine the information from different web resources, even if they use different terminologies and languages
Keyword Search Engine • Iphone example:I want to find the information of cheapest iphone. I can start form Google or Ebay to search whether there is someone selling the iphone. Then, I can collect all the useful information appearing on the searching result by myself.
Keyword Search Engine • Restaurant example:I want to find a restaurant with good quality and close to my home. Then my first step might be searching on the food website and finding the evaluation of some restaurants. After collecting some useful information, I can decide which restaurant is more suitable for me to have my dinner.
Semantic Search Enginedifferent result? • Restaurant example:We can type in what we need with our natural language. After computer receives our natural language request, it might further ask whether we can accept the price above 300 dollars or do we mind to have Italian food. • Allow us to interact with computer and type in more opinion with our natural language
Keyword Search Engine • Problem: synonyms • Example:When a user uses apple as a key word to search, search engine might feed back the results in fruit domain or Apple computer domain • If we search virus on the internet, we can find virus related to computer science field. And we can also find different definition of virus in biology and medicine domain.
Semantic Web • Usually put things in order according to the meaning of word • Advantage:It helps to search in domain knowledge. • Construing a tree structure can let the root has some relation to their children. One subclass can be an attributes or an object.
Semantic Search Engine • Extend the range of searching by Semantic Web • Use hierarchical and vertical structure to search data. This method related to specific domain knowledge
Semantic Search Engine • Hakia, Evri, Poweset, Cognition:We can use a natural language to describe our need when we do the search • Allow users use a word, a phrase or a sentence to search web pages
Semantic Search Engine • Example: • When I type in “Where is Columbia University?” • There must be a parser used to parse a sentence and analyze the structure of the sentence. • Does the word contains any knowledge?
Probabilistic latent semantic analysis • Example: • If we type in “the weather in New York” • The words “the” and “in” might appear many times in our corpus. “The” and “in” contains no knowledge in it although it appears usually. • The corresponding result should be more concentrate on “New York” and “weather” when we do the search
Semantic Search Engine • Difficulties:Users might type in a sentence with strange grammar structure or including some complicated grammar structure. Search engine can hardly understand this kind of strange sentences which it has never “learned” before.
Evri • Similar to a database system:tree diagram in Evri is similar to E/R diagram in a relational database system • It allows users connect to another website according to the meaning of the word and gives hyperlink an attribute according to its meaning Kaiser: COMS E6125
How to construct semantic search engine? • People disclose more personal preference to the search engine ->actually they are going to create their own personal semantic web and give a meaning for the material • Many users create their personalized semantic webs->search engine companies can aggregate all the semantic webs and construct a bigger semantic web
Advantages • The content of knowledge also can be updated from user contribution • Searching engines can analyze users’ behavior through this approach • Enables every user share its own semantic web and take advantages of other people’s semantic web
Challenge in implementation semantic search engine • How to parse the sentence? • Parser! • How to differentiate the synonyms/How to organize data? • Semantic Web!
Conclusion • Search less, understand more