Statistics with an upper case letter S refers to the science and discipline of Statistics, which can be defined as the **measurement of uncertainty**.

Statistics with a lower case letter s refers to numbers that summarise other numbers in some way. For example the arithmetic mean or average value of a sample of numbers is a statistic commonly used to describe the central location of the distribution of numbers in the population from which the sample was drawn.

The terms sample and population are very important in the language used by Statisticians. Many statistical methods are based upon drawing a sample at random from a population because it would be impractical to study the whole population. Samples drawn at random have mathematical properties that have enabled Statisticians to create numerical methods that measure how uncertain an investigator should be that their sample represents the population they are studying.

You should be familiar with the basic concepts of Statistics before you use this software. Please digest some introductory learning materials, such as Bland (2000) or selected web sites.

The following are basic elements of Statistics that you should understand:

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