# Statistics: Overview

Posted by Beetle B. on Sat 13 May 2017

## Populations, Samples and Processes

A census means you poll every member of the population.

Univariate vs bivariate or multivariate: Univariate means there’s only one variable under consideration.

Descriptive statistics merely describes the data, without drawing conclusions. Think computing the mean, standard deviation, plotting the data, etc.

Inferential statistics involves generalizing from the sample to the population.

Probability and statistics are the inverses of each other. In probability, the distribution of the population and its properties are known, and we calculate things. In statistics, we are estimating the distribution and trying to know the population.

Enumerative vs analytical studies:

• Enumerative is the “usual” case where a population exists and we are sampling from it. It is well understood and the conclusions are reliable.
• Analytical studies don’t have an actual population. As an example, you use samples for an existing industrial process and make conclusions about the next generation process. Never do this without a domain expert!