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Encyclopedia > Design of experiments

The first statistician to consider a methodology for the design of experiments was Sir Ronald A. Fisher. He described how to test the hypothesis that a certain lady could distinguish by flavor alone whether the milk or the tea was first placed in the cup. While this sounds like a frivolous application, it allowed him to illustrate the most important means of experimental design: A graph of a bell curve in a normal distribution showing statistics used in educational assessment, comparing various grading methods. ... Sir Ronald Fisher Sir Ronald Aylmer Fisher, FRS (17 February 1890 – 29 July 1962) was a British eugenicist, evolutionary biologist, geneticist and statistician. ... A hypothesis is a suggested explanation of a phenomenon or reasoned proposal suggesting a possible correlation between multiple phenomena. ...

Analysis of the design of experiments was built on the foundation of the analysis of variance, a collection of models in which the observed variance is partitioned into components due to different factors which are estimated and/or tested. Randomization is the process of making something random. ... Replication may mean: In biology: Self-replication, when a molecule (or any other pattern) makes a copy of itself DNA replication, the act of copying the genetic material of a cell (DNA) to a daughter cell Semiconservative replication, mechanism of DNA replication Other: replication (computer science), the provision of redundant... In the statistical theory of the design of experiments, blocking is the arranging of experimental units in groups (blocks) which are similar to one another. ... In mathematics, orthogonal is synonymous with perpendicular when used as a simple adjective that is not part of any longer phrase with a standard definition. ... A factorial experiment is a statistical study in which each observation is categorised according to more than one factor. ... This article needs to be cleaned up to conform to a higher standard of quality. ... In the scientific method, an experiment (Latin: ex-+-periri, of (or from) trying), is a set of actions and observations, performed in the context of solving a particular problem or question, to support or falsify a hypothesis or research concerning phenomena. ... In statistics, analysis of variance (ANOVA) is a collection of statistical models and their associated procedures which compare means by splitting the overall observed variance into different parts. ...

In 1950, Gertrude Mary Cox and William Cochran published the book Experimental Design which became the major reference work on the design of experiments for statisticians for years afterwards. Gertrude Mary Cox (1900-1978) was an influential American statistican and founder of the department of Experimental Statistics at North Carolina State University. ... William Cochran could refer to: William Thad Cochran, American politician William Gemmell Cochran British-American statistician. ...

Developments of the theory of linear models have encompassed and surpassed the cases that concerned early writers. Today, the theory rests on advanced topics in abstract algebra and combinatorics. In statistics the linear model can be expressed by saying where Y is an n×1 column vector of random variables, X is an n×p matrix of known (i. ... Abstract algebra is the field of mathematics concerned with the study of algebraic structures such as groups, rings and fields. ... Combinatorics is a branch of mathematics that studies collections (usually finite) of objects that satisfy specified criteria. ...

As with all other branches of statistics, there is both classical and Bayesian experimental design. This article needs to be cleaned up to conform to a higher standard of quality. ...

See also

Most scientific work starts with a question about the world we live in. ... In statistics, survey sampling is random selection of a sample from a finite population. ... In experimental design an independent variable is that variable which is measured, manipulated, or selected by the experimenter to determine its relationship to an observed phenomenon (the dependent variable). ... In experimental design, a dependent variable is a variable dependent on another variable (called the independent variable). ... A randomized controlled trial (RCT) is a form of clinical trial, or scientific procedure used in the testing of the efficacy of medicines or medical procedures. ... A graph of a bell curve in a normal distribution showing statistics used in educational assessment, comparing various grading methods. ...

External links

  Results from FactBites:
Design of Experiments (315 words)
When understanding your design space is important, a HEEDS DOE study is often the ideal approach to extract a great deal of useful information with as little computational or experimental effort as possible.
In a CAE-based DOE study, your CAE model is evaluated multiple times with the design variables set to different values in each run.
DOE studies based on physical experiments are performed in a similar manner, except that a physical experiment replaces each CAE run.
DOE Software: STATISTICA Design of Experiments Software by StatSoft (3484 words)
The options for analyzing all factorial, response surface, and mixture designs are general in nature, can handle unbalanced and incomplete designs, and give the user full control of the choice of models to be fitted to the data.
The fractional design generators and block generators of the design, as well as the matrix of aliases of main effects and interactions can also be reviewed.
In addition to the standard options available for all designs (adding runs, randomization, replications, factor highs and lows, etc.; refer to the description of 2**(k-p) designs) the user has the choice of star-points that are face-centered, or computed for rotatability, orthogonality, or both.
  More results at FactBites »



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