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:
- Document Processor - this prepares, processes, and inputs the documents, pages, or sites that users search against.
- 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.
- Search and Matching Function - this is based on which theoretical model of information retrieval underlies the system's design philosophy.
- 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
Issues
Algorithms
The algorithms that were initially used were fairly basic and objective. They were based such criterion as number of visits to a page or the number of pages that link to a certain page. The success and popularity of Google is attributed to their more subjective approach. Google implemented an algorithm that is meant to find what users are looking for instead of offering the most popular results, which is not always the same thing. The secrecy of their algorithm is what gives Google their competitive edge.