How Internet Search Engines Work"

The good news about the Internet and its most visible component, the World Wide Web, is that there are hundreds of millions of pages available, waiting to present information on an amazing variety of topics. The bad news about the Internet is that there are hundreds of millions of pages available, most of them titled according to the whim of their author, almost all of them sitting on servers with cryptic names. When you need to know about a particular subject, how do you know which pages to read? Internet search engines are special sites on the Web that are designed to help people find information stored on other sites. They search the Internet -- or select pieces of the Internet -- based on important words.They keep an index of the words they find, and where they find them.They allow users to look for words or combinations of words found in that index.

Reuters Corpora @ NIST In 2000, Reuters Ltd made available a large collection of Reuters News stories for use in research and development of natural language processing, information retrieval, and machine learning systems. This corpus, known as "Reuters Corpus, Volume 1" or RCV1, is significantly larger than the older, well-known Reuters-21578 collection heavily used in the text classification community. In Fall of 2004, NIST took over distribution of RCV1 and any future Reuters Corpora. You can now get these datasets by sending a request to NIST and by signing the agreements below. What's available The stories in the Reuters Corpus are under the copyright of Reuters Ltd and/or Thomson Reuters, and their use is governed by the following agreements: Organizational agreement This agreement must be signed by the person responsible for the data at your organization, and sent to NIST. Individual agreement Getting the corpus Download and print the Organizational and Individual agreement forms above. The article, Lewis, D.

instaGrok: Research Concept Mapping How Internet Search Engines Work" Once the spiders have completed the task of finding information on Web pages (and we should note that this is a task that is never actually completed -- the constantly changing nature of the Web means that the spiders are always crawling), the search engine must store the information in a way that makes it useful. There are two key components involved in making the gathered data accessible to users: The information stored with the dataThe method by which the information is indexed In the simplest case, a search engine could just store the word and the URL where it was found. To make for more useful results, most search engines store more than just the word and URL. Regardless of the precise combination of additional pieces of information stored by a search engine, the data will be encoded to save storage space. An index has a single purpose: It allows information to be found as quickly as possible. In English, there are some letters that begin many words, while others begin fewer.

reuters_corpus-90_cat.zip - text-analysis - Reuters Corpus, Volume 1, English language - 90 Categories - Collection of methods to analyse text content My favorites ▼ | Sign in Project Home Downloads Wiki Issues Source Terms - Privacy - Project Hosting Help Powered by Google Project Hosting Sweet Search ARGNet: Alternate Reality Gaming Network Stemming and lemmatization Next: Faster postings list intersection Up: Determining the vocabulary of Previous: Other languages. Contents Index For grammatical reasons, documents are going to use different forms of a word, such as organize, organizes, and organizing. The goal of both stemming and lemmatization is to reduce inflectional forms and sometimes derivationally related forms of a word to a common base form. am, are, is be car, cars, car's, cars' car The result of this mapping of text will be something like: the boy's cars are different colors the boy car be differ color However, the two words differ in their flavor. The most common algorithm for stemming English, and one that has repeatedly been shown to be empirically very effective, is Porter's algorithm (Porter, 1980). would map replacement to replac, but not cement to c. to oper. Exercises.

AR Games The MIT Teacher Education Program, in conjunction with The Education Arcade, has been working on creating "Augmented Reality" simulations to engage people in simulation games that combine real world experiences with additional information supplied to them by handheld computers. The first of these games, Environmental Detectives (ED), is an outdoor game in which players using GPS guided handheld computers try to uncover the source of a toxic spill by interviewing virtual characters and conducting large scale simulated environmental measurements and analyzing data. This game has been run at three sites, including MIT, a nearby nature center, and a local high school.