Type of site
|Owner||Wolfram Alpha LLC|
|Created by||Wolfram Research|
|Slogan(s)||Making the world’s knowledge computable.|
|Alexa rank||1,932 (March 2015)|
May 18, 2009 (official launch)|
May 15, 2009 (public launch)
|Written in||Wolfram Language|
Wolfram Alpha (also styled WolframAlpha and Wolfram|Alpha) is a computational knowledge engine or answer engine developed by Wolfram Research, which was founded by Stephen Wolfram. It is an online service that answers factual queries directly by computing the answer from externally sourced "curated data", rather than providing a list of documents or web pages that might contain the answer as a search engine might.
Wolfram Alpha, which was released on May 18, 2009, is based on Wolfram's earlier flagship product Mathematica, a computational platform or toolkit that encompasses computer algebra, symbolic and numerical computation, visualization, and statistics capabilities. Additional data is gathered from both academic and commercial websites such as the CIA's The World Factbook, the United States Geological Survey, a Cornell University Library publication called All About Birds, Chambers Biographical Dictionary, Dow Jones, the Catalogue of Life, CrunchBase, Best Buy, the FAA and optionally a user's Facebook account.
Users submit queries and computation requests via a text field. Wolfram Alpha then computes answers and relevant visualizations from a knowledge base of curated, structured data that come from other sites and books. The site "use[s] a portfolio of automated and manual methods, including statistics, visualization, source cross-checking, and expert review." The curated data makes Alpha different from semantic search engines, which index a large number of answers and then try to match the question to one.
Wolfram Alpha can only provide robust query results based on computational facts, not queries on the social sciences, cultural studies or even many questions about history where responses require more subtlety and complexity. It is able to respond to particularly-phrased natural language fact-based questions such as "Where was Mary Robinson born?" or more complex questions such as "How old was Queen Elizabeth II in 1974?" It displays its "Input interpretation" of such a question, using standardized phrases such as "age | of Queen Elizabeth II (royalty) | in 1974", the answer of which is "Age at start of 1974: 47 years", and a biography link. Wolfram Alpha does not answer queries which require a narrative response such as "What is the difference between the Julian and the Gregorian calendars?" but will answer factual or computational questions such as "June 1 in Julian calendar".
Mathematical symbolism can be parsed by the engine, which typically responds with more than the numerical results. For example, "lim(x->0) (sin x)/x" yields the correct limiting value of 1, as well as a plot, up to 235 terms (as of 2013) of the Taylor series, and (for registered users) a possible derivation using L'Hôpital's rule. It is also able to perform calculations on data using more than one source. For example, "What is the fifty-second smallest country by GDP per capita?" yields Nicaragua, $1160 per year.
Wolfram Alpha is written in 15 million lines of Wolfram Language code and runs on more than 10,000 CPUs. The database currently includes hundreds of datasets, such as "All Current and Historical Weather." The datasets have been accumulated over several years. The curated (as distinct from auto-generated) datasets are checked for quality either by a scientist or other expert in a relevant field, or someone acting in a clerical capacity who simply verifies that the datasets are "acceptable".
One example of a live dataset that Wolfram Alpha can use is the profile of a Facebook user, through inputting the "facebook report" query. If the user authorizes Facebook to share his or her account details with the Wolfram site, Alpha can generate a "personal analytics" report containing the age distribution of friends, the frequency of words used in status updates and other detailed information. 