The measurement of most outcomes in a population of subjects will vary. Whether you are measuring height, weight, blood pressure, or the change in any of these, there is usually variation between subjects. The collection of data on one of these variables is known as a distribution.
Descriptive Statistics summarizes observations made on a distribution. These summaries consists of:
03. Describing Magnitude of an Effect
References
1. Descriptive Statistics Lecture: University of Pittsburgh Supercourse: http://www.pitt.edu/~super1/lecture/lec0421/index.htm
2. Descriptive Statistics Calculator: http://www.redjade.net