Statistics

Statistics is a branch of mathematics dealing with data collection, analysis and presentation. In applying statistics to, for example, a scientific, industrial, or social problem, it is conventional to begin with a statistical population or a statistical model process to be studied. Populations can be diverse topics such as "all people living in a country" or "every atom composing a crystal". Statistics deals with every aspect of data, including the planning of data collection in terms of the design of surveys and experiments. See glossary of probability and statistics; when census data cannot be collected, statisticians collect data by developing specific experiment designs and survey samples. Representative sampling assures that inferences and conclusions can reasonably extend from the sample to the population as a whole. An experimental study involves taking measurements of the system under study, manipulating the system, taking additional measurements using the same procedure to determine if the manipulation has modified the values of the measurements.

In contrast, an observational study does not involve experimental manipulation. Two main statistical methods are used in data analysis: descriptive statistics, which summarize data from a sample using indexes such as the mean or standard deviation, inferential statistics, which draw conclusions from data that are subject to random variation. Descriptive statistics are most concerned with two sets of properties of a distribution: central tendency seeks to characterize the distribution's central or typical value, while dispersion characterizes the extent to which members of the distribution depart from its center and each other. Inferences on mathematical statistics are made under the framework of probability theory, which deals with the analysis of random phenomena. A standard statistical procedure involves the test of the relationship between two statistical data sets, or a data set and synthetic data drawn from an idealized model. A hypothesis is proposed for the statistical relationship between the two data sets, this is compared as an alternative to an idealized null hypothesis of no relationship between two data sets.

Rejecting or disproving the null hypothesis is done using statistical tests that quantify the sense in which the null can be proven false, given the data that are used in the test. Working from a null hypothesis, two basic forms of error are recognized: Type I errors and Type II errors. Multiple problems have come to be associated with this framework: ranging from obtaining a sufficient sample size to specifying an adequate null hypothesis. Measurement processes that generate statistical data are subject to error. Many of these errors are classified as random or systematic, but other types of errors can be important; the presence of missing data or censoring may result in biased estimates and specific techniques have been developed to address these problems. Statistics can be said to have begun in ancient civilization, going back at least to the 5th century BC, but it was not until the 18th century that it started to draw more from calculus and probability theory. In more recent years statistics has relied more on statistical software to produce tests such as descriptive analysis.

Some definitions are: Merriam-Webster dictionary defines statistics as "a branch of mathematics dealing with the collection, analysis and presentation of masses of numerical data." Statistician Arthur Lyon Bowley defines statistics as "Numerical statements of facts in any department of inquiry placed in relation to each other."Statistics is a mathematical body of science that pertains to the collection, interpretation or explanation, presentation of data, or as a branch of mathematics. Some consider statistics to be a distinct mathematical science rather than a branch of mathematics. While many scientific investigations make use of data, statistics is concerned with the use of data in the context of uncertainty and decision making in the face of uncertainty. Mathematical statistics is the application of mathematics to statistics. Mathematical techniques used for this include mathematical analysis, linear algebra, stochastic analysis, differential equations, measure-theoretic probability theory.

In applying statistics to a problem, it is common practice to start with a population or process to be studied. Populations can be diverse topics such as "all people living in a country" or "every atom composing a crystal". Ideally, statisticians compile data about the entire population; this may be organized by governmental statistical institutes. Descriptive statistics can be used to summarize the population data. Numerical descriptors include mean and standard deviation for continuous data types, while frequency and percentage are more useful in terms of describing categorical data; when a census is not feasible, a chosen subset of the population called. Once a sample, representative of the population is determined, data is collected for the sample members in an observational or experimental setting. Again, descriptive statistics can be used to summarize the sample data. However, the drawing of the sample has been subject to an element of randomness, hence the established numerical descriptors from the sample are due to uncertainty.

To still draw meaningful conclusions about the entire population, in

Outline of academic disciplines

An academic discipline or field of study is a branch of knowledge and researched as part of higher education. A scholar's discipline is defined by the university faculties and learned societies to which she or he belongs and the academic journals in which she or he publishes research. Disciplines vary between well-established ones that exist in all universities and have well-defined rosters of journals and conferences and nascent ones supported by only a few universities and publications. A discipline may have branches, these are called sub-disciplines. There is no consensus on how some academic disciplines should be classified, for example whether anthropology and linguistics are disciplines of the social sciences or of the humanities; the following outline is provided as topical guide to academic disciplines. Biblical studies Religious studies Biblical Hebrew, Biblical Greek, Aramaic Buddhist theology Christian theology Anglican theology Baptist theology Catholic theology Eastern Orthodox theology Protestant theology Hindu theology Jewish theology Muslim theology Biological anthropology Linguistic anthropology Cultural anthropology Social anthropology Archaeology Accounting Business management Finance Marketing Operations management Edaphology Environmental chemistry Environmental science Gemology Geochemistry Geodesy Physical geography Atmospheric science / Meteorology Biogeography / Phytogeography Climatology / Paleoclimatology / Palaeogeography Coastal geography / Oceanography Edaphology / Pedology or Soil science Geobiology Geology Geostatistics Glaciology Hydrology / Limnology / Hydrogeology Landscape ecology Quaternary science Geophysics Paleontology Paleobiology Paleoecology Astrobiology Astronomy Observational astronomy Gamma ray astronomy Infrared astronomy Microwave astronomy Optical astronomy Radio astronomy UV astronomy X-ray astronomy Astrophysics Gravitational astronomy Black holes Interstellar medium Numerical simulations Astrophysical plasma Galaxy formation and evolution High-energy astrophysics Hydrodynamics Magnetohydrodynamics Star formation Physical cosmology Stellar astrophysics Helioseismology Stellar evolution Stellar nucleosynthesis Planetary science Also a branch of electrical engineering Pure mathematics Applied mathematics Astrostatistics Biostatistics Academia Academic genealogy Curriculum Multidisciplinary approach Interdisciplinarity Transdisciplinarity Professions Classification of Instructional Programs Joint Academic Coding System List of fields of doctoral studies in the United States List of academic fields Abbott, Andrew.

Chaos of Disciplines. University of Chicago Press. ISBN 978-0-226-00101-2. Oleson, Alexandra; the Organization of knowledge in modern America, 1860-1920. ISBN 0-8018-2108-8. US Department of Education Institute of Education Sciences. Classification of Instructional Programs. National Center for Education Statistics. Classification of Instructional Programs: Developed by the U. S. Department of Education's National Center for Education Statistics to provide a taxonomic scheme that will support the accurate tracking and reporting of fields of study and program completions activity. Complete JACS from Higher Education Statistics Agency in the United Kingdom Australian and New Zealand Standard Research Classification Chapter 3 and Appendix 1: Fields of research classification. Fields of Knowledge, a zoomable map allowing the academic disciplines and sub-disciplines in this article be visualised. Sandoz, R. Interactive Historical Atlas of the Disciplines, University of Geneva

ArXiv

ArXiv is a repository of electronic preprints approved for posting after moderation, but not full peer review. It consists of scientific papers in the fields of mathematics, astronomy, electrical engineering, computer science, quantitative biology, mathematical finance and economics, which can be accessed online. In many fields of mathematics and physics all scientific papers are self-archived on the arXiv repository. Begun on August 14, 1991, arXiv.org passed the half-million-article milestone on October 3, 2008, had hit a million by the end of 2014. By October 2016 the submission rate had grown to more than 10,000 per month. ArXiv was made possible by the compact TeX file format, which allowed scientific papers to be transmitted over the Internet and rendered client-side. Around 1990, Joanne Cohn began emailing physics preprints to colleagues as TeX files, but the number of papers being sent soon filled mailboxes to capacity. Paul Ginsparg recognized the need for central storage, in August 1991 he created a central repository mailbox stored at the Los Alamos National Laboratory which could be accessed from any computer.

Additional modes of access were soon added: FTP in 1991, Gopher in 1992, the World Wide Web in 1993. The term e-print was adopted to describe the articles, it began as a physics archive, called the LANL preprint archive, but soon expanded to include astronomy, computer science, quantitative biology and, most statistics. Its original domain name was xxx.lanl.gov. Due to LANL's lack of interest in the expanding technology, in 2001 Ginsparg changed institutions to Cornell University and changed the name of the repository to arXiv.org. It is now hosted principally with eight mirrors around the world, its existence was one of the precipitating factors that led to the current movement in scientific publishing known as open access. Mathematicians and scientists upload their papers to arXiv.org for worldwide access and sometimes for reviews before they are published in peer-reviewed journals. Ginsparg was awarded a MacArthur Fellowship in 2002 for his establishment of arXiv; the annual budget for arXiv is $826,000 for 2013 to 2017, funded jointly by Cornell University Library, the Simons Foundation and annual fee income from member institutions.

This model arose in 2010, when Cornell sought to broaden the financial funding of the project by asking institutions to make annual voluntary contributions based on the amount of download usage by each institution. Each member institution pledges a five-year funding commitment to support arXiv. Based on institutional usage ranking, the annual fees are set in four tiers from $1,000 to $4,400. Cornell's goal is to raise at least $504,000 per year through membership fees generated by 220 institutions. In September 2011, Cornell University Library took overall administrative and financial responsibility for arXiv's operation and development. Ginsparg was quoted in the Chronicle of Higher Education as saying it "was supposed to be a three-hour tour, not a life sentence". However, Ginsparg remains on the arXiv Scientific Advisory Board and on the arXiv Physics Advisory Committee. Although arXiv is not peer reviewed, a collection of moderators for each area review the submissions; the lists of moderators for many sections of arXiv are publicly available, but moderators for most of the physics sections remain unlisted.

Additionally, an "endorsement" system was introduced in 2004 as part of an effort to ensure content is relevant and of interest to current research in the specified disciplines. Under the system, for categories that use it, an author must be endorsed by an established arXiv author before being allowed to submit papers to those categories. Endorsers are not asked to review the paper for errors, but to check whether the paper is appropriate for the intended subject area. New authors from recognized academic institutions receive automatic endorsement, which in practice means that they do not need to deal with the endorsement system at all. However, the endorsement system has attracted criticism for restricting scientific inquiry. A majority of the e-prints are submitted to journals for publication, but some work, including some influential papers, remain purely as e-prints and are never published in a peer-reviewed journal. A well-known example of the latter is an outline of a proof of Thurston's geometrization conjecture, including the Poincaré conjecture as a particular case, uploaded by Grigori Perelman in November 2002.

Perelman appears content to forgo the traditional peer-reviewed journal process, stating: "If anybody is interested in my way of solving the problem, it's all there – let them go and read about it". Despite this non-traditional method of publication, other mathematicians recognized this work by offering the Fields Medal and Clay Mathematics Millennium Prizes to Perelman, both of which he refused. Papers can be submitted in any of several formats, including LaTeX, PDF printed from a word processor other than TeX or LaTeX; the submission is rejected by the arXiv software if generating the final PDF file fails, if any image file is too large, or if the total size of the submission is too large. ArXiv now allows one to store and modify an incomplete submission, only finalize the submission when ready; the time stamp on the article is set. The standard access route is through one of several mirrors. Sev

Academic journal

An academic or scholarly journal is a periodical publication in which scholarship relating to a particular academic discipline is published. Academic journals serve as permanent and transparent forums for the presentation and discussion of research, they are peer-reviewed or refereed. Content takes the form of articles presenting original research, review articles, book reviews; the purpose of an academic journal, according to Henry Oldenburg, is to give researchers a venue to "impart their knowledge to one another, contribute what they can to the Grand design of improving natural knowledge, perfecting all Philosophical Arts, Sciences."The term academic journal applies to scholarly publications in all fields. Scientific journals and journals of the quantitative social sciences vary in form and function from journals of the humanities and qualitative social sciences; the first academic journal was Journal des sçavans, followed soon after by Philosophical Transactions of the Royal Society, Mémoires de l'Académie des Sciences.

The first peer-reviewed journal was Medical Essays and Observations. The idea of a published journal with the purpose of " people know what is happening in the Republic of Letters" was first conceived by Eudes de Mazerai in 1663. A publication titled Journal littéraire général was supposed to be published to fulfill that goal, but never was. Humanist scholar Denis de Sallo and printer Jean Cusson took Mazerai's idea, obtained a royal privilege from King Louis XIV on 8 August 1664 to establish the Journal des sçavans; the journal's first issue was published on 5 January 1665. It was aimed at people of letters, had four main objectives: review newly published major European books, publish the obituaries of famous people, report on discoveries in arts and science, report on the proceedings and censures of both secular and ecclesiastical courts, as well as those of Universities both in France and outside. Soon after, the Royal Society established Philosophical Transactions of the Royal Society in March 1665, the Académie des Sciences established the Mémoires de l'Académie des Sciences in 1666, which more focused on scientific communications.

By the end of the 18th century, nearly 500 such periodical had been published, the vast majority coming from Germany and England. Several of those publications however, in particular the German journals, tended to be short lived. A. J. Meadows has estimated the proliferation of journal to reach 10,000 journals in 1950, 71,000 in 1987. However, Michael Mabe warns that the estimates will vary depending on the definition of what counts as a scholarly publication, but that the growth rate has been "remarkably consistent over time", with an average rates of 3.46% per year from 1800 to 2003. In 1733, Medical Essays and Observations was established by the Medical Society of Edinburgh as the first peer-reviewed journal. Peer review was introduced as an attempt to increase the pertinence of submissions. Other important events in the history of academic journals include the establishment of Nature and Science, the establishment of Postmodern Culture in 1990 as the first online-only journal, the foundation of arXiv in 1991 for the dissemination of preprints to be discussed prior to publication in a journal, the establishment of PLOS One in 2006 as the first megajournal.

There are two kinds of article or paper submissions in academia: solicited, where an individual has been invited to submit work either through direct contact or through a general submissions call, unsolicited, where an individual submits a work for potential publication without directly being asked to do so. Upon receipt of a submitted article, editors at the journal determine whether to reject the submission outright or begin the process of peer review. In the latter case, the submission becomes subject to review by outside scholars of the editor's choosing who remain anonymous; the number of these peer reviewers varies according to each journal's editorial practice – no fewer than two, though sometimes three or more, experts in the subject matter of the article produce reports upon the content and other factors, which inform the editors' publication decisions. Though these reports are confidential, some journals and publishers practice public peer review; the editors either choose to reject the article, ask for a revision and resubmission, or accept the article for publication.

Accepted articles are subjected to further editing by journal editorial staff before they appear in print. The peer review can take from several weeks to several months. Review articles called "reviews of progress," are checks on the research published in journals; some journals are devoted to review articles, some contain a few in each issue, others do not publish review articles. Such reviews cover the research from the preceding year, some for longer or shorter terms; some journals are enumerative. Yet others are evaluative; some journals are published in series, each covering a complete subject field year, or covering specific fields through several years. Unlike original research article

Revista Colombiana de Estadística

The Revista Colombiana de Estadística is a biannual peer-reviewed scientific journal on statistics published by the National University of Colombia. It covers research on statistics, including applications, statistics education, the history of statistics; the Revista Colombiana de Estadística was established in 1968. During the first years, the journal only published papers in Spanish but since 1985 it publishes papers in English; the journal stopped publication between 1969 and 1979. In 1979, it was relaunched by Luis Thorin and since 1981 the publication has been continuous with two issues per year. Since 2011 the Journal only publishes articles in English language; the Revista Colombiana de Estadística is abstracted and indexed in Scopus, SciELO, Current Index to Statistics, Mathematical Reviews, Zentralblatt MATH, Redalyc and Publindex. According to the Journal Citation Reports, the journal has a 2014 impact factor of 0.179. Comparison of statistics journals List of statistics journals Official website Category A1 Publindex

International Standard Serial Number

An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.

The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.

The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.

Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the