CSC 379 SUM2008:Week 2, Group 3

Search Engines

Search engines fill an important role in our lives, helping us locate information within a wide array of multimedia. However many ethical considerations are involved in their operation; the ordering of rankings, the range of content indexed (or not), and how advertisements are incorporated, are a few. Broadly examine the ethics of search engine operation and use.

• http://www.i-r-i-e.net/inhalt/003/003_hinman.pdf
• http://www.i-r-i-e.net/inhalt/003/003_editorial.pdf
• http://www.boingboing.net/2008/04/04/usfunded-health-sear.html
• http://www.scu.edu/ethics/publications/submitted/search-engine-panel.html

Function

A search engine is an information retrieval system that match queries with an index it creates. Search engines consist of four essential modules:

1. Document Processor - this prepares, processes, and inputs the documents, pages, or sites that users search against.
2. Query Processor - this consist of seven possible steps
   • Tokenizing usually by breaking inputs into strings separated by white space.
   • Parsing operators like reserved punctuation or reserved terms in specialized format (e.g., AND, OR). This may also include boolean, adjacency, or proximity operators.
   • Stop list and stemming might contain words from commonly occurring querying phrases. Engines may drop these two steps.
   • Creating the query depends on the method used to do the matching.
   • Query expansion employs synonyms to optimize the search results.
   • Query term weighting is used to judge the importance of each term in the query.
3. Search and Matching Function - this is based on which theoretical model of information retrieval underlies the system's design philosophy.
4. Ranking Capability - this is done several ways
   • Term frequency
   • Location of terms
   • Link analysis
   • Popularity
   • Date of Publication
   • Length
   • Proximity of query terms
   • Proper nouns

External Links

How a Search Engine Works