Statistics is the mathematical science involved in the application of quantitative principles to the collection, analysis, and presentation of numerical data. The practice of statistics utilizes data from some population in order to describe it meaningfully, to draw conclusions from it, and make informed decisions. The population may be a community, an organization, a production line, a service counter, or a phenomenon such as the weather. Statisticians determine which quantitative model is correct for a given type of problem and they decide what kinds of data should be collected and examined. Applied statistics concerns the application of the general methodology to particular problems. This often calls for use of the techniques of computer-based data analysis. Some examples of statistical problems are: Interpretation of evidence linking environmental factors and disease, Design of experiments to evaluate effectiveness of pharmaceuticals, Mining data to discover target segments in the population, Market research to estimate demand for a new product,
Opinion polling in politics,
Estimation of the size of an animal population to aid in establishing regulations for conservation,
Reliability studies for determining warranties,
Improving the quality of a service or manufactured item,
Analysis of errors in scientific experiments, and
Prediction of stock market prices.
Statisticians are key contributors to scientific methodologies. They use their quantitative knowledge to the design data collection schemes, process the data, analyze the data, and interpret the results. Further, statisticians often make critical evaluations on the reliability of data and whether inferences drawn from can be made confidently. They also help to identify misleading abuses of data that may be portraying an inaccurate account of a situation. Theoretical statistics concerns general classes of problems and the development of general methodology. Statisticians generally develop models based on probability theory. Probability theory is the branch of mathematics which develops models for “chance variations” or “random phenomena.”
It originated as a discipline when mathematicians of the 17th century began calculating the odds in various games of chance. It was soon realized how to make applications of the theory they developed to the study of errors in experimental measurements and to the study of human mortality (for example, by life insurance companies). Probability theory is now a major field with widespread applications in science and engineering. A few examples are: Modeling the occurrence of sunspots to improve radio communication, Modeling and control of congestion on highways, and Reliability theory to evaluate the chance that a space vehicle will function throughout a mission. According to the American Statistical Association, job characteristics of persons in the statistical professions include the following activities: Use data to solve problems in a wide variety of fields, Apply mathematical and statistical knowledge to social, economic, medical, political, and ecological problems, Work individually and/or as part of an interdisciplinary team, Travel to consult with other professionals or attend conferences, seminars, and continuing education activities, and Advance the frontiers of statistics and probability through education and research.