A data set (or dataset) is a collection of data, usually presented in tabular form. Debt AIDS Trade in Africa (or DATA) is a Multinational non-government organization founded in January 2002 in London by U2 's Each column represents a particular variable. Each row corresponds to a given member of the data set in question. It lists values for each of the variables, such as height and weight of an object or values of random numbers. Each value is known as a datum. Debt AIDS Trade in Africa (or DATA) is a Multinational non-government organization founded in January 2002 in London by U2 's The data set may comprise data for one or more members, corresponding to the number of rows.

Historically, the term originated in the mainframe field, where it had a well-defined meaning, very close to contemporary computer file. Mainframes (often colloquially referred to as Big Iron) are Computers used mainly by large organizations for critical applications typically bulk data A data set, or dataset, is a Computer file having a record organization. A computer file is a block of Arbitrary Information, or resource for storing information which is available to a Computer program and is usually This topic is not covered here.

In the simplest case, there is only one variable, and then the data set consists of a single column of values, often represented as a list.

The values may be numbers, such as real numbers or integers, for example representing a person's height in centimeters, but may also be nominal data (i. In Mathematics, the real numbers may be described informally in several different ways The integers (from the Latin integer, literally "untouched" hence "whole" the word entire comes from the same origin but via French The level of Measurement of a Variable in Mathematics and Statistics is a classification that is used to describe the nature of information e. , not consisting of numerical values), for example representing a person's ethnicity. A number is an Abstract object, tokens of which are Symbols used in Counting and measuring. More generally, values may be of any of the kinds described as a level of measurement. The level of Measurement of a Variable in Mathematics and Statistics is a classification that is used to describe the nature of information For each variable, the values will normally all be of the same kind. However, there may also be "missing values", which need to be indicated in some way. In Statistics, missing values are a common occurrence Several statistical methods have been developed to deal with this problem

In statistics data sets usually come from actual observations obtained by sampling a statistical population, and each row corresponds to the observations on one element of that population. Statistics is a mathematical science pertaining to the collection analysis interpretation or explanation and presentation of Data. Sampling is that part of Statistical practice concerned with the selection of individual observations intended to yield some knowledge about a population of concern In Statistics, a statistical population is a set of entities concerning which Statistical inferences are to be drawn often based on a Random sample Data sets may further be generated by algorithms for the purpose of testing certain kinds of software. In Mathematics, Computing, Linguistics and related subjects an algorithm is a sequence of finite instructions often used for Calculation Some modern statistical analysis software such as PSPP still present their data in the classical dataset fashion. PSPP is a Free software application for analysis of sampled data

Classic data sets

Several classic data sets have been used extensively in the statistical literature:

• Iris flower data set - multivariate data set introduced by Ronald Fisher (1936). Statistics is a mathematical science pertaining to the collection analysis interpretation or explanation and presentation of Data. The Iris flower data set or Fisher's Iris data set is a Multivariate Data set introduced by Sir Ronald Aylmer Fisher (1936 as an example of Sir Ronald Aylmer Fisher, FRS ( 17 February 1890 – 29 July 1962) was an English Statistician, Evolutionary ^[1]
• Categorical data analysis - Data sets used in the book, An Introduction to Categorical Data Analysis, by Agresti are provided on-line by StatLib.
• Robust statistics - Data sets used in Robust Regression and Outlier Detection (Rousseeuw and Leroy, 1986). These are Statistical procedures which can be used for the analysis of categorical data: regression Analysis of variance Robust statistics provides an alternative approach to classical statistical methods Provided on-line at the University of Cologne.
• Time series - Data used in Chatfield's book, The Analysis of Time Series, are provided on-line by StatLib.
• Extreme values - Data used in the book, An Introduction to the Statistical Modeling of Extreme Values are provided on-line by Stuart Coles, the book's author. In Statistics, Signal processing, and many other fields a time series is a sequence of Data points measured typically at successive times spaced at (often
• Bayesian Data Analysis - Data used in the book, Bayesian Data Analysis, are provided on-line by Andrew Gelman, one of the book's authors.
• The Bupa liver data, used in several papers in the machine learning (data mining) literature.

References

External links

• StatLib--Datasets Archive
• StatLib--JASA Data Archive
• GCMD - The Global Change Master Directory contains more than 20,000 descriptions of Earth science data sets and services covering all aspects of Earth and environmental sciences.