Domains Yahoo

Yahoo! este un portal și motor de căutare, considerat a fi fost primul motor de căutare performant. În prezent, oferă unele dintre cele mai populare servicii online, toate bazate pe un cont unic: un serviciu de e-mail (Yahoo! Mail), având spațiu de stocare nelimitat, un program de conversație pe internet (Yahoo! Messenger), știri (Yahoo! News), călătorii (Yahoo! Travel) și multe altele.

Yahoo! a fost la început denumit „Ghidul lui Jerry și David despre rețeaua mondială de calculatoare”. Numele Yahoo! provine de la expresia: „Yet Another Hierarchical Officious Oracle”.

Servicii și site-uri deținute de Yahoo!

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  Yahoo! 360°

Yahoo! 360° este un site unde utilizatorii își pot crea pagini personale și blog-uri. De când s-a lansat pe 29 martie 2005, a adunat peste două milioane de membrii. Acesta era doar pe bază de invitație până pe 24 iunie 2005 iar în mod curent este disponibil pentru persoanele cu vârsta peste 13 ani.

• Yahoo! Advertising

Yahoo! Advertising este o combinație de servicii de publicitate deținute de Yahoo!.

• Yahoo! Answers –

Yahoo! Answers este un serviciu unde utilizatorii pun întrebări și răspund la întrebările celorlați. Utilizatorii „sunt plătiți” și „plătesc” puncte. Pentru a pune întrebări, se „plătesc” 5 puncte iar pentru a răspunde la întrebări utilizatorului i se dau 2 puncte. Serviciul era cunoscut înainte sub numele de Yahoo! Ask.

• Yahoo! Avatars

Yahoo! Avatars permite utilizatorilor să creeze personaje care să îi reprezinte, numite avatare, care pot fi afișate pe Yahoo! Messenger și pe profilul Yahoo! 360° al utilizatorului.

• Yahoo! Autos

Yahoo! Autos permite utilizatorului să cumpere automobile noi și folosite.

• Yahoo! Assistant

Yahoo! Assistant este un obiect ajutător pentru Internet Explorer. A fost creat de Beijing 3721 Technology și numit 3721 Assistant, dar a fost redenumit Yahoo! Assistant după ce Yahoo! a achiziționat Beijing 3721 Technology.

• Yahoo! Briefcase

Yahoo! Briefcase este un serviciu de stocare de fișiere gratuit.

• Yahoo! Buzz Log

Yahoo! Buzz Log reține și analizează căutările efectuate prin Yahoo! Search și le actualizează săpătămânal.

• Yahoo! Developer Network

Yahoo! Developer Network oferă resurse pentru producătorii de software care folosesc site-uri și servicii Yahoo!

• Yahoo! Directory

Yahoo! a fost la început un director web. După ce acesta s-a extins, această secțiune a devenit Yahoo! Directory.

• Yahoo! Finance

Yahoo! Finance oferă informații financiare.

• Yahoo! Gallery

Yahoo! Gallery este un director de aplicații făcute folosind tehnologii Yahoo!.

• Yahoo! Games

Yahoo! Games permite utilizatorilor să joace jocuri online cum ar fi șah și table , against each other. Utilizatorii pot intra în multele camere și pot căuta utilizatori cu care vor să se dueleze. Majoritatea jocurilor sunt applet-uri Java, pe când altele necesită descărcare. Când Yahoo! a achiziționat ClassicGames.com în 1997, acesta a devenit serviciu Yahoo!

• Yahoo! Geocities

Yahoo! GeoCities este un serviciu de stocare a paginilor web ce oferă 15 MO. S-a format la sfârșitul anului 1994 ca Beverly Hills Internet și a fost achiziționat de Yahoo! în 1999 .

• Yahoo! Groups liste de e-mail-uri,

Yahoo! Groups este un serviciu gratuit de grupuri și liste de e-mail-uri. S-a format atunci când Yahoo! a achiziționat eGroups.

• Yahoo! Local

Yahoo! Local este capabil să caute slujbe locale și să le afișeze pe o hartă.

• Yahoo! Mail

Yahoo! a achiziționat Four11 pe 8 octombrie 1997 și serviciul său de poștă electronică prin internet, Rocketmail a devenit Yahoo! Mail. Spațiul de stocare este nelimitat.

• Yahoo! Maps

Yahoo! Maps oferă informații din trafic și hărți.

• Yahoo! Messenger

Yahoo! Messenger este un serviciu de mesagerie instant lansat de Yahoo! în 1999. Facilitățile lui cuprind „IMvironement”, mesaje de stare particularizate, plug-in-uri și altele.

• Yahoo! Mobile

Yahoo! Mobile este un site pentru telefoanele mobile folosit predominant în Marea Britanie. Oferă descărcări cum ar fi tonuri de apel.

• Yahoo! Movies

Yahoo! Movies oferă filme, informații despre filme și altele.

• Yahoo! Music

Yahoo! Music oferă videoclipuri muzicale și radio prin internet (LAUNCHcast), un serviciu gratuit cunoscut și sub numele de Yahoo! Music Unlimited.

• Yahoo! News oferă actualizări de știri și povești de top de la Yahoo News,inclusiv internațional,național,afaceri,divertisment,sport,meteo,tehnologie și știri ciudate.

• Yahoo! Photos

Yahoo! Photos este un serviciu de partajare a fotografiilor similar cu Flickr, care este, de asemenea deținut de Yahoo!. Utilizatorii au un spațiu nelimitat de stocare dar sunt acceptate numai fotografiile JPG. Yahoo! Photos se închide pe 20 septembrie 2007 pentru a se axa pe Flickr.

• Yahoo! Search

Yahoo! Search este un motor de căutare performant.

• Yahoo! Shopping

Yahoo! Shopping permite utilizatorului să caute, să compare și să cumpere produse pe internet.

• Yahoo! Sports

Yahoo! Sports oferă știri din sport incluzând scoruri și statistici.

• Yahoo! Tech

Yahoo! Tech oferă sfaturi pentru cumpărarea și utilizarea electronicelor.

• Yahoo! Travel

Yahoo! Travel oferă ghiduri de călătorie.

• Yahoo! TV

Yahoo! TV orare TV dar și înregistrări.

• Yahoo! Video

Yahoo! Video este un site pentru partajarea filmelor.

• Yahoo! Widgets

Yahoo! Widgets este un sistem de accesorii ce rulează pe toate atât pe Windows cât și pe distribuțiile de Linux. Era cunoscut sub numele de Konfabulator înainte ca Yahoo! să îl cumpere.

• Yahoo! Kids

Yahoo! Kids este versiunea pentru copii a portalului Yahoo!

• Bix

Bix este un site de concursuri achiziționat de Yahoo în 2006.

• blo.gs

blo.gs este un director de blog-uri actualizate recent cumpărat de Yahoo în, iunie 2005.

• Dialpad

Dialpad a fost o companie de telefonie, devenită Yahoo! Voice.

Source: www.wikipedia.org

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Google Scholar is a freely accessible web search engine that indexes the full text of scholarly literature across an array of publishing formats and disciplines. Released in beta in November 2004, the Google Scholar index includes most peer-reviewed online journals of Europe and America's largest scholarly publishers, plus scholarly books other non-peer reviewed journals. It is similar in function to the freely available Scirus from Elsevier,CiteSeerX, and getCITED. It is also similar to the subscription-based tools, Elsevier's Scopus and Thomson ISI'sWeb of Science. Its advertising slogan — "Stand on the shoulders of giants" — is a nod to the scholars who have contributed to their fields over the centuries, providing the foundation for new intellectual achievements.

Google Scholar arose out of a discussion between Alex Verstak and Anurag Acharya,^[1] both of whom were then working on building Google's main web index.

History

In 2006, in response to release of Microsoft's Windows Live Academic Search, a potential competitor for Google Scholar, a citation importing feature was implemented using bibliography managers (such as RefWorks, RefMan, EndNote, and BibTeX). Similar features are also part of other search engines, such as CiteSeer and Scirus.

In 2007, Acharya announced that Google Scholar had started a program to digitize and host journal articles in agreement with their publishers, an effort separate fromGoogle Books, whose scans of older journals do not include the metadata required for identifying specific articles in specific issues.^[4]

In 2011, Google removed Scholar from the toolbars on its search pages, making it both less easily accessible and invisible to users who were not already aware of its existence.

Features and specifications

Google Scholar allows users to search for digital or physical copies of articles, whether online or in libraries.^[5] “Scholarly” searches will appear using the references from “’full-text journal articles, technical reports, preprints, theses, books, and other documents, including selected Web pages that are deemed to be “scholarly.’”^[6]Because most of Google Scholar's search results link directly to commercial journal articles, a majority of the time users will only be able to access a brief summary of the articles topics, as well as small amounts of important information regarding the article, and possibly have to pay a fee to access the entire article.^[6] Google Scholar is as easy to use as with the regular Google web search, especially with the helpfulness of the "advanced search" option, which can automatically narrow search results to a specific journal or article.^[7] The most relevant results for the searched keywords will be listed first, in order of the author's ranking, the number of references that are linked to it and their relevance to other scholarly literature, and the ranking of the publication that the journal appears in.^[8]

Using its "group of" feature, it shows the available links to journal articles. In the 2005 version, this feature provided a link to both subscription-access versions of an article and to free full-text versions of articles; for most of 2006, it provided links to only the publishers' versions. Since December 2006, it has provided links to both published versions and major open access repositories, but still does not cover those posted on individual faculty web pages;^{[citation needed]} access to such self-archived non-subscription versions is now provided by a link to Google, where one can find such open access articles.

Through its "cited by" feature, Google Scholar provides access to abstracts of articles that have cited the article being viewed.^[9] It is this feature in particular that provides the citation indexing previously only found in Scopus and Web of Knowledge. Through its "Related articles" feature, Google Scholar presents a list of closely related articles, ranked primarily by how similar these articles are to the original result, but also taking into account the relevance of each paper.^[10]

As of March 2012, Google Scholar is not yet available to the Google AJAX API.

Google Scholar’s legal database of US cases is extensive. Users can search and read published opinions of US state appellate and supreme court cases since 1950, US federal district, appellate, tax and bankruptcy courts since 1923 and US Supreme Court cases since 1791.^[9] Google Scholar embeds clickable citation links within the case and the How Cited tab allows lawyers to research prior case law and the subsequent citations to the court decision.^[11] The Google Scholar Legal Content Star Paginator extension inserts Westlaw and LexisNexis style page numbers in line with the text of the case.^[12]

Ranking algorithm

While most academic databases and search engines allow users to select one factor (e.g. relevance, citation counts, or publication date) to rank results, Google Scholar ranks results with a combined ranking algorithm in a "way researchers do, weighing the full text of each article, the author, the publication in which the article appears, and how often the piece has been cited in other scholarly literature".^[8] Research has shown that Google Scholar puts high weight especially on citation counts^[13] and words included in a document's title.^[14] As a consequence the first search results are often highly cited articles.

Limitations and criticism

Use of Google Scholar does not automatically grant searchers access to publications available through subscription sites. The full texts of articles in Google Scholar are not necessarily available freely to all searchers, though searchers with access through an institution such as a research laboratory or university may be able to access select articles freely. Some articles found through Google Scholar are hosted by sites that allow searchers to subscribe or purchase the full text of their articles.

Some searchers consider Google Scholar of comparable quality and utility to commercial databases,^[15][16] even though its user interface (UI) is still in beta. The reviews recognize that its "cited by" feature in particular poses serious competition to Scopus and ISI Web of Knowledge, although, in a study limited to the biomedical field, the citation information found in Google Scholar have found to be sometimes inadequate, and less often updated.^[17] Another important issue is that the relative coverage of Google Scholar varies by discipline compared to other general databases. ^[18]

A significant problem with Google Scholar is the secrecy about its coverage.^{[editorializing]} Some publishers do not allow it to crawl their journals. Elsevier journals were not included before mid-2007, when Elsevier began to make most of its ScienceDirect content available to Google Scholar and Google's web search.^[19] As of February 2008 the absentees still included the most recent years of the American Chemical Society journals. Google Scholar does not publish a list of scientific journals crawled, and the frequency of its updates is unknown. It is therefore impossible to know how current or exhaustive searches are in Google Scholar. Nonetheless, it allows easy access to published articles without the difficulties encountered in some of the most expensive commercial databases^[20].

Google Scholar puts high weight on citation counts in its ranking algorithm and therefore is being criticised for strengthening the Matthew effect^[13]; as highly cited papers appear in top positions they gain more citations while new papers hardly appear in top positions and therefore get less attention by the users of Google Scholar and hence fewer citations.

Google Scholar has problems identifying publications on the arXiv preprint server correctly. Interpunctuation characters in titles produce wrong search results, and authors are assigned to wrong papers, which leads to erroneous additional search results. Some search results are even given without any comprehensible reason.^[21][22]

Google Scholar is vulnerable to spam.^[23] Researchers from the University of California, Berkeley and Otto-von-Guericke University Magdeburg demonstrated that citation counts on Google Scholar can be manipulated and complete non-sense articles created with SCIgen were indexed from Google Scholar.^[24] They concluded that citation counts from Google Scholar should only be used with care especially when used to calculate performance metrics such as the h-index or impact factor. Although Google Scholar does not compute the h-index itself, several downstream web sites use its data. The practicality of manipulating h-index calculators byspoofing Google Scholar was demonstrated in 2010 by Cyril Labbe from Joseph Fourier University, who managed to rank "Ike Antkare" ahead of Albert Einstein by means of a large set of SCIgen-produced documents citing each other (effectively an academic link farm).^[25]

Google Scholar is also not able to shepardize case law, as Westlaw and Lexis can.

Google Scholar url: http://scholar.google.com

source: www.wikipedia.org

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