chance . The phrase Statistical hypothesis testing test of significance was coined by Ronald Fisher . ref name Fisher1925 Critical tests of this kind may be called tests of significance, and when ... 0.001 . If a Statistical hypothesis testing test of significance gives a p value lower ... this could have happened by coincidence, a 0.001 level of statisticalsignificance is being implied ... Oliver & Boyd ref In some situations it is convenient to express the statisticalsignificance ... nuclear and particle physics, it is common to express statisticalsignificance in units of sigma , the standard deviation of a Gaussian distribution . A statisticalsignificance of math n sigma math ... extensive discussion of the use of the concept of statisticalsignificance and in particular of its ... noise ratio conceptualisation of significanceStatisticalsignificance can be considered to be the confidence ... The Cult of StatisticalSignificance How the Standard Error Costs Us Jobs, Justice, and Lives . Ann ... Significance Rationale, Validity and Utility, Volume 1 of series Introducing Statistical Methods, Sage Publications Ltd, ISBN 978 0 76195205 3 argues that statisticalsignificance is useful in certain ... www.ericdigests.org 1995 1 testing.htm The Concept of StatisticalSignificance Testing Article by Bruce ... StatisticalSignificance Category Hypothesis testing ca Significaci estad stica cs Statistick ... from the first. R. A. Fisher 1925 . Statistical Methods for Research Workers , Edinburgh Oliver ... enough to be utterly unimportant. Many researchers urge that tests of significance should always be accompanied ... to have arisen by chance is known as the significance level or critical p value in traditional Ronald Fisher Fisherian statistical hypothesis testing , the p value is the probability of observing data ... statistical hypothesis testing framework is the Neyman Pearson lemma Neyman Pearson frequentist school ... when it is in fact false Type II error . More typically, the significance level of a test is such that the probability ... more details
Wiktionarypar significanceSignificance can refer to with purpose and importance Meaning disambiguation Meaning In semiotics, the meaning semiotics meaning assigned to a sign Significant figures or significant digits, the precision of a numerical value Significance policy debate , a stock issue in policy debate Statisticalsignificance , the probability that a result is not due to chance Significance magazine , 2004 , a magazine published by the Royal Statistical Society. disambig de Signifikanz ... more details
Statistical Society and the American Statistical Association receive Significance . ref http magazine.amstat.org ... http www.rss.org.uk main.asp?page 1712 Significance page on Royal Statistical Society s website http www.amstat.org publications significance index.cfm Significance page on American Statistical Association s website http onlinelibrary.wiley.com journal 10.1111 ISSN 1740 9713 Publisher ... Significance Magazine Category Royal Statistical Society Category American Statistical Association ...Italic title Infobox magazine title Significance image file SigCover.jpg image caption Significance cover, December 2009 company Royal Statistical Society and American Statistical Association circulation 28,000 September 2010 frequency Quarterly language English category Statistics editor Julian Champkin publisher Wiley Blackwell firstdate March 2004 country UK USA website http www.significancemagazine.org Significance magazine issn 1740 9705 COI date November 2010 Significance , established in 2004, is a magazine published quarterly by both the Royal Statistical Society and the American Statistical Association ref http www.amstat.org about pressreleases ASA&RSSAnnounceJointPubSignificance.pdf ref . The major part of the content consists of articles on topics of statistical interest presented at a level suited to a general audience. It is not a research journal and articles are not peer reviewed ref http www.wiley.com bw submit.asp?ref 1740 9705&site 1 ref . The founding editor was Helen Joyce ref cite news url http commentisfree.guardian.co.uk helen joyce profile.html location London work The Guardian ref , now at The Economist, and Frank Duckworth also served on its Editorial Board . The current editor is Julian Champkin ref http www.rss.org.uk main.asp?page 1712 ref . As well as ordinary articles in the magazine itself, ref http www3.interscience.wiley.com journal 118500352 home .... ref cite web url http www.wiley.com bw vi.asp?ref 1740 9705&site 1 title Significance Information ... more details
. ref name Jacobson, N. 1991 Jacobson, N., & Truax, P. 1991 . Clinical significance A statistical ... of scores or subscores that is Statisticalsignificance statistically significant , unlikely ... calculations of significanceStatisticalsignificance main statisticalsignificanceStatisticalsignificance tends to be used in the context of null hypothesis significance testing NHST . NHST answers ... New Orleans, LA, Feb 7, 2008 . ref . In terms of testing clinical treatments, statisticalsignificance ... policies regarding statisticalsignificance and effect size. Theory & Psychology, 10, 413 425 ... Just as there are many ways to calculate statisticalsignificance and practical significance ...Clinical significance was first proposed by Jacobson, Follette, and Revenstorf ref Jacobson, N.S., Follette ... and evaluating clinical significance. Behavior Therapy, 15 4 . ref as a way to answer the question ...? Jacobson and Truax later defined clinical significance as the extent to which therapy moves ... of therapy. ref name Jacobson, N. 1991 Clinical significance is also a consideration when ... data and the client s history that corroborates the relevance of the statistical difference, to establish ... alternative hypothesis should be accepted. Given the nature of NHST, and its common misuse, statisticalsignificance does not yield information about magnitude of effect, practical significance, nor clinical significance ref Haase, R.F., Ellis, M.V., Ladany, N. 1989 .Multiple Criteria for Evaluating ... ref Clinical Significance Clinical Significance and Practical Significance are NOT the Same Things. Online ... it is that the statistical test of the treatment would erroneously indicate that the treatment is effective? Practical significance and effect size main effect size Clinical significance and practical significance are often erroneously used interchangeably ref name Peterson, L. 2008 Peterson, L. 2008 . Clinical Significance Clinical Significance and Practical Significance are NOT the Same Things ... more details
Significance arithmetic is a set of rules sometimes called significant figure rules for approximating the propagation of uncertainty in scientific or statistical calculations. These rules can be used to find the appropriate number of significant figures to use to represent the result of a calculation. If a calculation is done without analysis of the uncertainty involved, a result that is written with too many significant figures can be taken to imply a higher Arithmetic precision precision than is known, and a result that is written with too few significant figures results in an avoidable loss of precision. Understanding these rules requires a good understanding of the concept of significant figures significant and insignificant figures . The rules of significance arithmetic are an approximation based on statistical rules for dealing with probability distributions. See the article on propagation of uncertainty for these more advanced and precise rules. Significance arithmetic rules rely on the assumption that the number of significant figures in the operand s gives accurate information ... by measurement. Multiplication and division using significance arithmetic When multiplying or dividing ... not the position of the significant figures. For instance, using significance arithmetic ... more accurate would be 64 8 . Addition and subtraction using significance arithmetic When adding or subtracting ... place. Rounding rules Because significance arithmetic involves rounding, it is useful to understand ... be that the outcome is inherently statistical, and is best described by the expression 1.234 0.056 ..., a completely certain number may be insignificant. Significance is not the same as significant digits . Digit counting is not as rigorous a way to represent significance as specifying the uncertainty ... Arithmetic FAQ Is the decimal arithmetic significance arithmetic? http www.av8n.com physics ... of significance arithmetic and significant figures. http ostermiller.org calc sigfig.html Significant ... more details
Orphan date March 2011 Track significance , in Particle physics high energy collision experiment s, is defined as the ratio between the impact parameter of a track distance from the primary vertex and the estimated error in it. Formula math S a o Error a o math References Unreferenced date January 2010 Reflist Category Particle physics physics stub ... more details
Unreferenced date September 2009 Loss of significance is an undesirable effect in calculations using floating point floating point arithmetic. It occurs when an operation on two numbers increases relative error substantially more than it increases absolute error , for example in subtracting two large and nearly equal numbers. The effect is that the number of significant digit accurate significant digits in the result is reduced unacceptably. Ways to avoid this effect are studied in numerical analysis . In floating point arithmetic, only a limited number of digits of the number are maintained floating point numbers can only approximate most real numbers. Example For the purposes of this example, if the reader is not familiar with binary numbers, bits can be considered as decimal digits. Consider the real binary number 1.001111111 A floating point representation of this number on a machine that keeps 4 floating point bits would be 1.001, which is fairly close the difference is very small in comparison with either of the two numbers. Now perform the calculation 1.001111111 1 The real answer, accurate to 7 significant bits, is 0.001111111 However, on the 4 bit floating point machine, the calculation yields 1.001 1.000 0.001 Whereas the original numbers are significant in all of the first 4 bits, their floating point difference is only accurate in its first nonzero bit. This amounts to loss of information. This phenomenon is relevant for any size Floating Point number. Instead of 4 significant bits, an IEEE standard single precision floating point number has 23 significant bits and 1 sign bit. Additionally, the phenomenon can also be demonstrated with decimal numbers. The following example demonstrates Loss of Significance for a Decimal floating point data type with 10 significant digits Consider the real decimal number 0.1234567891234567890. A floating point representation ... of numerical analysis is to avoid or minimize loss of significance in calculations. If the underlying ... more details
The power of a Statistical hypothesis testing statistical test is the probability that the test will reject ..., the concept of power is used to make comparisons between different statistical testing procedures for example, between a parametric and a nonparametric test of the same hypothesis. Background Statistical test s use data from Sampling statistics sample s to assess, or make statistical inference inferences about, a Statistical population population . In the concrete setting of a two sample comparison ... to them, and the mean score of one group is compared to that of the other group using a statistical ... which is known as a Type I error , or false positive . Factors influencing power Statistical power ... situation, but at a minimum, power nearly always depends on the following three factors the statisticalsignificance criterion used in the test the magnitude of the effect of interest in the population the sample size used to detect the effect A significance criterion is a statement of how unlikely ... out a less conservative test by using a larger significance criterion. This increases the chance of obtaining ... in smaller samples. Increasing sample size is often the easiest way to boost the statistical power of a test. The precision with which the data are measured also influences statistical power. Consequently ... Guide to Effect Sizes An Introduction to Statistical Power, Meta Analysis and the Interpretation of Research ... interval to be less than a given value. Many statistical analyses involve the estimation of several ..., the only relevant power pertains to the single quantity that will undergo formal statistical ... variances, their powers will differ as well. Any statistical analysis involving multiple comparisons ... hypotheses at the desired significance level. In Bayesian statistics , hypothesis testing of the type ... footnotes date January 2010 Notes references References Jacob Cohen statistician Cohen, J. Statistical ... statmath stat all power power.pdf Hypothesis Testing and Statistical Power of a Test http ... more details
Unreferenced date January 2007 In statistical mechanics , the statistical weight is the relative probability possibly unnormalized of a particular feature of a state. If the energy associated with the feature is E , the statistical weight is given by the Boltzmann factor e sup E kT sup , where k is the Boltzmann constant and T is the temperature in kelvin s. The statistical weight is a convenient shorthand that is often used in transfer matrix solutions of problems in statistical mechanics . DEFAULTSORT Statistical Weight Category Statistical mechanics Thermodynamics stub ... more details
standards of statistical randomness to slot machine s. Tests The first tests for random numbers were published by M.G. Kendall and Bernard Babington Smith in the Journal of the Royal Statistical Society in 1938. They were built on statistical tools such as Pearson s chi square test that were developed ... not display random behavior. Kendall and Smith s original four tests were statistical hypothesis testing ... a given degree of significance generally 5 , then it was judged to be, in their words locally random ... be useless for a number of statistical applications. As random number sets became more and more ... pages 93 118 isbn 0201896842 ref Maurer s Universal Statistical Test. See also Checking if a coin is fair Normal number Randomness Random number Statistical hypothesis testing One time pad Randomness .... Babington Smith, Randomness and Random Sampling Numbers, Journal of the Royal Statistical Society ... Statistical randomness es Aleatoriedad estad stica ... more details
Unreferenced date October 2007 In statistics , for example in statistical quality control , a statistical assembly is a collection of parts or components which makes up a statistical unit . Thus a statistical unit, which would be the prime item of concern, is made of discrete components like organs or machine parts. The reliability of the statistical unit is, in part, determined by the reliability of the components in the statistical assembly, and by their interactions. Much of the observation of a statistical assembly requires special preparation of the unit, which demands that the intervention must not prejudice the observations. A simple version of this kind of research uses the stimulus response model . In other contexts, statistical assembly refers to the process of constructing a manufactured item which must be carefully specified to contain given amounts of nonuniformity within it. External links http adcats.et.byu.edu ADCATS Theory AutoCAD Analyzer 1 2D Overview 1 2D Overview .html Category Statistical terminology Category Quality control Category Survival analysis statistics stub ... more details
Statistical noise is the colloquialism for recognized amounts of unexplained variation in a sample statistics sample . See errors and residuals in statistics . Examples Gaussian noise External links cite web url http www.faqs.org faqs ai faq neural nets part3 section 2.html title How does noise affect generalization? date 2001 05 21 publisher faqs.org accessdate 2008 07 13 http www.wisegeek.com what is statistical noise.htm What is Statistical Noise? Category Noise Category Statistical deviation and dispersion statistics stub ... more details
Refimprove date December 2009 Statistical physics is the branch of physics that uses methods of probability theory and statistics , and particularly the Mathematics mathematical tools for dealing with large populations and approximations, in solving physical problems. It can describe a wide variety of fields with an inherently stochastic nature. Its applications include many problems in the fields of physics, biology , chemistry , neurology , and even some social sciences, such as sociology . Citation needed date September 2010 In particular, statistical mechanics develops the phenomenological results of thermodynamics from a probabilistic examination of the underlying microscopic systems. Historically, one of the first topics in physics where statistical methods were applied was the field of mechanics , which is concerned with the motion of particles or objects when subjected to a force. Statistical mechanics Statistical mechanics provides a framework for relating the microscopic properties ..., classical mechanics , and quantum mechanics at the microscopic level. Because of this history, the statistical physics is often considered synonymous with statistical mechanics or statistical thermodynamics . ref group note This article presents a broader sense of the definition of statistical physics ref A statistical approach can work well in classical systems when the number of degrees of freedom ... is not possible, or not really useful. Statistical mechanics can also describe work in non linear ... s , or plasma physics . Although some problems in statistical physics can be solved analytically using ... computers to simulate or approximate solutions. A common approach to statistical problems is to use a Monte Carlo simulation to yield insight into the dynamics of a complex system. See also Statistical ensemble mathematical physics Statistical ensemble Statistical field theory Mean sojourn time Dynamics ... Reflist group note References Reflist DEFAULTSORT Statistical Physics Categories Category Statistical ... more details
Infobox Software name Statistical Lab screenshot Deleted image removed Image statlab.jpg 250px caption The Statistical Lab Statistiklabor developer Freie Universit t Berlin latest release version 3.5.0.1 3.7 Beta latest release date 12 November 2007 operating system Microsoft Windows XP Windows XP , Microsoft Windows 2000 Windows 2000 genre Statistics Statistical analysis license GPL for non commercial users website http www.statistical lab.de The computer program Statistical Lab Statistiklabor is an explorative and interactive toolbox for statistical analysis and visualization of data. It supports educational applications of statistics in business sciences , economics , social sciences and humanities . The program is developed and constantly advanced by the Center for Digital Systems of the Free University of Berlin . Their website states that the source code is available to private users ... a private user who already has a copy any of their employees will do . Simple or complex statistical problems can be simulated, edited and solved individually with the Statistical Lab. It can be extended ... of underlying data. The Statistical Lab is the successor of Statistik interaktiv . In contrast to the commercial SPSS the Statistical Lab is didactically driven. It is focused on providing facilities for users with little statistical experience. It combines data frames, contingency tables ... calculations, the Statistical Lab uses the Engine R programming language R , which is a free implementation ... en index.html Homepage of the Statistical Lab in English http tutorials.statistiklabor.de Statistical Lab Tutorial for newbies English versions available http forum.statistiklabor.de forum for Statistical Lab users bilingual English and German http statistiklabor.tigris.org Tigris.org Source Code of the Statistical Lab discontinued, source code now available in the download area of the main ... berlin.de Homepage of the Center for Digital Systems Category Statistical software Category Windows ... more details
A statistical consultant provides statistical advice and guidance to clients interested in making decisions through the analysis or collection of data. Clients often need statistical advice to answer questions in business , medicine , biology , genetics , forestry , agriculture , fisheries , wildlife management , psychology , law , industry . The role of the statistical consultant varies from project to project, and can include any or all of the following design of experiments and research studies plotting data measurement instruments choosing, constructing & analyzing determination of adequate sample size to detect a hypothesized effect determination of an adequate Sampling statistics sampling procedure for a study, statistical survey survey or experiment supervision of data collection to ensure elements of the population statistics population are being sampled correctly statistical analyses e.g., analysis of variance , Regression analysis regression , etc. of data to address research hypotheses the write up of statistical results for grant proposals, manuscripts, professional conferences, or other presentations. Many university universities run statistical consulting services for researchers and students within their institution, and some also offer external consulting on commercial terms. There are also many private statistical consulting firms that work with companies and individuals. See also Statistician Management consulting List of University Statistical Consulting Centers References Boen, J. R., & Zahn, D. A. 1982 . Human Side of Statistical Consulting. Wadsworth Publishing Company. Cabrera, J., McDougall, A. 2002 . Statistical Consulting. Springer. Derr, J. 1999 . Statistical Consulting A Guide to Effective Communication. Duxbury Press. Hand, D. J., & Everitt, B.S. 1987 . The Statistical Consultant in Action. Cambridge University Press. Ad r, H.J., Mellenbergh ... of Statistical Consultants provided by the Royal Statistical Society No More Links PLEASE BE CAUTIOUS ... more details
Orphan date February 2009 A statistical database is a database used for statistics statistical analysis purposes. It is an OLAP instead of OLTP system, although this term precedes that modern decision, and classical statistical databases are often closer to the relational model than the multidimensional database multidimensional model commonly used in OLAP systems today. Statistical databases often incorporate support for advanced statistical analysis techniques, such as correlations, which go beyond SQL . They also pose unique security concerns, which were the focus of much research, particularly in the late 1970s and early to mid 1980s. Security in statistical databases In a statistical database, it is often desired to allow query access only to aggregate datas, not individual records. Securing such a database is a difficult problem, since intelligent users can use a combination of aggregate queries to derive information about a single individual. Some common approaches are only allowing aggregate queries SUM, COUNT, AVG, STDEV, etc. rather than returning exact values for sensitive data like income, only return which partition it belongs to e.g. 35k 40k return imprecise counts e.g. ... stalled reference 3 below showed that, in general, securing statistical databases was an impossible ... so tightly as to be incapable of abuse, they would then be useless for practical statistical purposes. To quote The conclusion is that statistical databases are almost always subject to compromise. Severe restrictions on allowable query set sizes will render the database useless as a source of statistical ... trier.de ley db conf ssdbm Statistical and Scientific Database Management SSDBM An important ... E. Denning, Secure statistical databases with random sample queries, ACM Transactions on Database ... de Jonge, Compromising statistical databases responding to queries about means, ACM Transactions on Database ..., Jan Schl rer, A fast procedure for finding a tracker in a statistical database, ACM Transactions ... more details
Statistical literacy is a term used to describe an individual s or group s ability to understand statistics . Statistical literacy is necessary for citizens to understand material presented in publications ... to critically evaluate statistical material and to appreciate the relevance of statistically based approaches to all aspects of life in general. ref Dodge, Y. 2003 The Oxford Dictionary of Statistical Terms , OUP. ISBN 0 19 920613 9 ref ref Wallman, K. 1993 Enhancing statistical literacy Enriching our society. J. American Statistical Association , 88, 1&ndash 8 ref ref http www.stat.auckland.ac.nz iase publications isr 02.Gal.pdf Gal, I. 2002 . Adults statistical literacy Meaning, components, responsibilities with Discussion . International Statistical Review , 70 1 , 1 51. ref Aspects of statistical literacy Many official statistical agencies such as Statistics Canada and the Australian Bureau ... ref http www.stat.auckland.ac.nz iase islp The International Statistical Literacy Project ref of the International Statistical Institute is the only international organization whose focus is to promote national programs and drives to increase the statistical literacy of all members of society ..., use statistics. People involved in these fields generally have studied the meaning of statistical ... course in statistics as part of a professional program. Each day people are inundated with statistical ..., and statistical literacy is a necessary skill to help one decide what experts mean and which ... of data that may seem valid. The aim of statistical literacy proponents is to improve the public ..., but the quality of such polls varies considerably. Some understanding of the statistical technique ... spent in the design of the questions and polling strategy. Statistical literacy is necessary to understand ... Heiberger,R.M., Holland, B. 2004 Statistical Analysis and Data Display . Springer. ISBN 0 387 40270 ... 2010 Gambling is one setting in which a lack of statistical literacy can be costly. Citation ... more details
Statistical epidemiology is an emerging branch of the disciplines of epidemiology and biostatistics that aims to Bring more statistical rigour to bear in the field of epidemiology Recognise the importance of applied statistics , especially with respect to the context in which statistical methods are appropriate and inappropriate Aid and improve our interpretation of observations Introduction The science of epidemiology has had enormous growth, particularly with charity and government funding. Many researchers have been trained to conduct studies, requiring multiple skills ranging from liaising with clinical staff to the statistical analysis of complex data , such as using Bayesian method s. The role of a Statistical Epidemiologist is to bring the most appropriate methods available to bear on observational study from medical research, requiring a broad appreciation of the underpinning methods and their context of applicability and interpretation. The earliest mention of this phrase was in an article by Wilson EB Cancer 1963 16 510 5 http www3.interscience.wiley.com cgi bin abstract 112661763 ABSTRACT?CRETRY 1&SRETRY 0 , taking a critical look at the way in which statistical methods were developing and being applied in the science of epidemiology. Academic recognition There are two Professors of Statistical Epidemiology in the United Kingdom http www.leeds.ac.uk medhealth light staff ... ide research groups stats Imperial College , London and a Statistical Epidemiology group Oxford University . Related fields Statistical epidemiology draws upon quantitative methods from fields ... Biometric Society The http www.amstat.org index.cfm?fuseaction main American Statistical Association The http www.rss.org.uk main.asp?page 0 Royal Statistical Society The http www.bca.edu.au Biostatistics ... EB. A critical look at statistical epidemiology. Cancer 1963 16 510 5. http www3.interscience.wiley.com ... of application of statistics Category Statistical terminology Category Biostatistics ... more details
See Statistics Statistical test Data analysis Bayesian analysis Mathematical proof . The term statistical ... of data under specified assumptions and hypotheses, this is a statistical proof . Examples of the assumptions are that the data are Statistical independence independent and have an underlying ... statistical test , the ratio of probabilities of an event occurring under each of two hypotheses ... that there is statistical proof of one hypothesis. Since the assumptions of mathematical statistics ..., as in the medical, natural, and social sciences . In that case, the term statistical proof is still sometimes used to refer to the outcome of a statistical test. ref Optimism is no longer merely the product of gut feelings but is supported by statistical proof both from the providers themselves ... and Protection ref ref I don t have any statistical proof of this, but I firmly believe that cheating ... Newspaper ref ref Based on clear statistical proof about which combination of design works most successfully ... press release ref In these statistical proofs , with assumptions that are only probably true ... mathematical tools and methods are employed. Bayesian analysis &mdash A statistical proof in Bayesian ... a year or two to have the statistical proof needed to confirm its presence http www.channel4.com news articles science technology qa the large hadron collider 2449067 ref , which may result in statistical ... 2008 Exploratory data analysis &mdash Statistical proof may refer to a scatter plot or product ... uses &mdash Statistical proof may colloquially refer to raw data where the data makes the conclusion obvious . ref Southern Cal s defensive line dominated Ohio State last weekend. Here s statistical ... use of statistical proof is often interchangeable with a colloquial use of mathematical proof , even ... appear from a distance to be points, is statistical proof of the existence of a gravitational force ... , and others, the expression statistical proof may be used in a well defined manner, or colloquially ... more details
otheruses4 the journal Statistical Science the mathematical science of statistics Statistics Infobox Journal title Statistical Science cover discipline Statistics language English website http www.imstat.org sts publisher Institute of Mathematical Statistics country United States USA history 1986 to present frequency ISSN 0883 4237 OCLC 12143452 LCCN sn98 23316 impact 3.523 impact year 2009 link1 http projecteuclid.org handle euclid.ss link1 name Access via Project Euclid JSTOR 08834237 Statistical Science is a review journal published by the Institute of Mathematical Statistics . The founding editor was Morris H. DeGroot . Further reading cite journal url http www.imstat.org sts degroot.pdf title Editorial The purpose of Statistical Science first Morris H last DeGroot authorlink Morris H. DeGroot journal Statistical Science volume 1 pages 1 2 External links http www.imstat.org sts Statistical Science home page Statistics journals Category Institute of Mathematical Statistics Category Statistics journals socialscience journal stub ... more details
Statistical fluctuations are fluctuations in quantities derived from many identical random processes. They are fundamental and unavoidable. It can be proved that the relative fluctuations reduce as the square root of the number of identical processes. Statistical fluctuations are responsible for many results of statistical mechanics and thermodynamics , and phenomena such as shot noise in electronics. Description When a number of random processes occur, it can be shown that the outcomes fluctuate vary in time and that the fluctuations are proportional to the square root of the number of processes. Examples As an example that will be familiar to all, if a fair Coin flipping coin is tossed many times and the number of heads and tails counted, the ratio of heads to tails will be very close to 1 about as many heads as tails but after only a few throws, outcomes with a significant excess of heads over tails or vice versa are common if an experiment with a few throws is repeated over and over, the outcomes will fluctuate a lot. An electric current so small that not many electrons are involved flowing through a p n junction is susceptible to statistical fluctuations as the actual number of electrons per unit time the current will fluctuate this produces detectable and unavoidable electrical noise known as shot noise . not a very good stub yet, but such an important phenomenon in all physics that it really needs an article Unreferenced date February 2011 No footnotes date February 2011 Category Statistical randomness Category Stochastic processes Category Statistical mechanics Probability stub Statistics stub ... more details
A statistical parameter is a parameter that indexes a family of probability distribution s. It can be regarded as a numerical characteristic of a population or a model. ref Everitt, B.S. 2002 The Cambridge Dictionary of Statistics. CUP. ISBN 0 521 81099 X ref Among parametric family parameterized families of distributions are the normal distribution s, the Poisson distribution s, the binomial distribution s, and the exponential distribution s. The family of normal distribution s has two parameters, the mean and the variance if these are specified, the distribution is known exactly. The family of chi squared distribution s, on the other hand, has only one parameter, the number of degrees of freedom. In statistical inference , parameters are sometimes taken to be unobservable, and in this case the statistician s task is to infer what he can about the parameter based on observations of random variables distributed according to the probability distribution in question, or, more concretely stated, based on a random sample taken from the population of interest. In other situations, parameters may be fixed by the nature of the sampling procedure used or the kind of statistical procedure being carried out for example, the number of degrees of freedom statistics degrees of freedom in a Pearson s chi squared test . Even if a family of distributions is not specified, quantities such as the mean and variance can still be regarded as parameters of the distribution of the population from which a sample is drawn. Statistical procedures can still attempt to make inferences about such population parameters. Parameters of this type are given names appropriate to their roles, including location parameter dispersion parameter or scale parameter shape parameter Where a probability distribution ... is to a statistical population population as a statistic is to a statistical sample sample . See ... fitting References Reflist Category Statistical theory Category Statistical terminology Category Theory ... more details
Image statsol.jpg 150px right link http www.statistical solutions software.com StatSol br Statistical Solutions is a developer and distributor of statistical software mainly in the niche clinical trials market. The origins of this company can be traced to 1984 with the establishment of a company called BMDP statistical software, a Los Angeles based company with a European subsidiary based in Cork, Ireland . BMDP launched the very first statistical software package, named after the company designed for use by general as opposed to niche markets. In exchange for government funding BMDP made the algorithms behind its software package available to the public domain. Mary Byrne who would later become the CEO and managing director of Statistical Solutions, lead a buyout of the European subsidiary in 1995. Thus the former subsidiary became an independent Irish firm by the name of Statistical Solutions. Initially Statistical Solutions had intended to operate in the general application software market however a number of events triggered the redirection of the company s focus. They set about developing a new and innovative software programme to address a statistical phenomenon called missing data which threatened to compromise the validity of clinical trials. With the aid of Harvard scholar Dr. Donald Rubin ref Donald Rubin s Harvard Webpage http www.stat.harvard.edu faculty page.php?page ... the same time Statistical Solutions also successfully negotiated the global exclusive distribution .... ref Ken Deal 2004 http statistical solutions software.com wp content uploads 2009 11 Ken Deal Missing Something.pdf ref As a Cork based company, Statistical Solutions are members of IT Cork. ref http www.itcork.ie index.cfm page viewCompanyProfile memberCompanyId 387 ref Statistical Solutions ... dVWJKYTfSJM. References reflist External links http www.statistical solutions software.com Statistical Solutions webpage Category Software companies of Ireland Category Statistical software ... more details
. Statistical techniques can be used to determine validity, reliability, and statisticalsignificance ...Multiple issues cleanup January 2008 rewrite April 2009 Sociology Statistical survey is a method used to collect in a systematic way, information from a sample of individuals. Although most people are familiar with public opinion surveys that are reported in the press, most surveys are not public opinion polls such as political polling , but are used for scientific purposes. Surveys provide important information for all kinds of research fields, e.g., marketing research, psychology , health professionals and sociology . ref http whatisasurvey.info ref A survey may focus on different topics such as preferences e.g., for a presidential candidate , behavior smoking and drinking behavior , or factual information e.g., income , depending on its purpose. Since survey research is always based on a sample of the population, the success of the research is dependent on the representativeness of the population of concern see also sampling statistics . Modes of Data Collection There are several ways of administering a survey. The choice between administration modes is influenced by several factors, including 1 costs, 2 coverage of the target population, 3 flexibility of asking questions, 4 respondents willingness to participate and 5 response accuracy. Different methods create mode effect s that change how respondents answer. The most common modes of administration are listed ref Mellenbergh ... and statistical analysis can begin not suitable for issues that may require clarification respondents ... that can be read by PSPP , DAP software DAP or other statistical analysis software data sets created ... Association http www.amstat.org sections srms Survey Research Methods Section of the American Statistical ... Survey Question Bank Social surveys Statistics collection state collapsed DEFAULTSORT Statistical Survey ... estat stico simple Statistical survey sv Surveyunders kning zh ... more details
Encyclopedia
top
