- For Wikipedia statistics, see m:Statistics
Statistics is the science and practice of developing human knowledge through the use of empirical data expressed in quantitative form. It is based on statistical theory which is a branch of applied mathematics. Within statistical theory, randomness and uncertainty are modelled by probability theory. Because one aim of statistics is to produce the
"best" information from available data, some authors consider statistics a branch of decision theory. Statistical practice includes the planning, summarizing, and interpreting of observations, allowing
for variability and uncertainty.
Origin
The word statistics comes from the modern Latin phrase statisticum
collegium (lecture about state affairs), from which came the Italian word statista meaning "statesman" or
"politician" (cf. status) and the
German Statistik, originally designating the analysis of data
about the state). It acquired the meaning of the collection and classification of data generally in the early nineteenth century.
It was introduced into English by Sir John Sinclair Thus, the
original principal purpose of statistics was data to be used by governmental and (often centralized) administrative bodies. The
collection of data about states and localities continues, largely through national and international statistical services; in particular,
censuses provide regular information about the population. Today, however, the use of statistics has broaded far beyond the service of a state or government,
to include such areas as business, natural and social sciences, and medicine, among others.
Statistical methods
We describe our knowledge (and ignorance) mathematically and attempt to learn more from whatever we can observe. This requires
us to
- plan our observations to control
their variability (experiment design),
- summarize a collection of observations to feature their
commonality by suppressing details (descriptive
statistics), and
- reach consensus about what the observations tell us
about the world we observe (statistical inference).
In some forms of descriptive statistics, notably data mining, the second
and third of these steps become so prominent that the first step (planning) appears to become less important. In these
disciplines, data often are collected outside the control of the person doing the analysis, and the result of the analysis may be
more an operational model than a consensus report about the world.
Specialized disciplines
Some sciences use applied statistics so extensively that
they have specialized terminology. These disciplines
include:
Statistics form a key basis tool in business and manufacturing as well. It is used to understand measurement systems
variability, control processes (as in statistical
process control or SPC), for summarizing data, and to make data-driven decisions. In these roles it is a key tool, and
perhaps the only reliable tool.
Software
Modern statistics is supported by computers to perform some of the very large and complex calculations required.
Whole branches of statistics have been made possible by computing, for example neural networks.
The computer revolution has implications for the future of statistics, with a new emphasis on 'experimental' statistics.
A list of statistical packages in common use:
References
Lindley, D. Making Decisions. John
Wiley. Second Edition 1985. ISBN 0471908088
External links
General sites and organizations
Link collections
Online courses and textbooks
Statistical software
Other resources
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