Statistics is the collection, analysis, and presentation of numerical data. According to the Occupational Handbook of the Bureau of Labor Statistics, statisticians design surveys and experiments, then collect and interpret the resulting information or data. In doing so, they often apply their knowledge of statistical methods to a particular subject area, such as biology, economics, engineering, medicine, or psychology. They use statistical techniques to predict population growth or economic conditions, develop quality control tests for manufactured products, assess the nature of environmental problems, analyze legal and social problems, or help business managers and government officials make decisions and evaluate the results of new programs.
Some statisticians develop new statistical methods.
Often statisticians are able to obtain information about a group of people or things by surveying a small portion, called a sample, of the group. For example, to determine the size of the total audience for particular programs, television rating services ask only a few thousand families, rather than all viewers, which programs they watch. Statisticians decide where and how to gather the data, determine the type and size of the sample group, and develop the survey questionnaire or reporting form. They also prepare instructions for workers who will collect and tabulate the data. Finally, statisticians analyze, interpret, and summarize the data, usually using sophisticated statistical computer software packages.