# Basic Definitions *Descriptive statistics* are mathematical expressions which describe a given data set. Mean, median, and mode are classic examples. These are used to understand a current or past population, but not extrapolate future trends. *Inferential statistics* are mathematical models to attempt to extrapolate new information from existing data. Linear regression and trend analysis in general are examples of inferential statistics. While descriptive statistics can be done on any size data set (though for small sets they aren't as necessary), inferential statistics generally need a relatively larger set to be accurate and useful. *Probabilities* run a strange gambit in between describing a data set and potentially inferring future states. Probabilities can move anywhere between describing a coin flip to complex models like Monte-Carlo simulations and Random Forests. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://katt.gitbook.io/wiki/math/definitions.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.