Descriptive statistics
Descriptive statistics is a field of statistics that summarise information about a sample, as opposed to inferential statistics, which use the data to draw inferences about a population.
Descriptive statistics should be familiar to you from high school. The purpose of including this topic in ENGN2226 is that using descriptive statistics is usually the first step in understanding data about your population.
Example applications
Descriptive statistics are used widely in many disciplines. In engineering, statistics is often used in process control and reliability engineering, such as efforts to improve efficiency or reduce error. Using statistical models can allow for a more informed approach to improving reliability than if you were to react to each data point.
Fundamentals
Broadly, there are two types of descriptive statistics:
- measures of central tendency, such as the mean, mode, and median
- measures of spread, such as range, quartiles and standard deviation
For the purposes of ENGN2226, these values should be both described through calculation and contextualised graphically.
Key concepts
- an overview of key descriptive statistics concepts
- an example that walks through how to calculate the key descriptive statistics
- advice to the student engineer on how to use descriptive statistics to understand data in a system
Core resources
-
Weiss, N.A., 2012, The Nature of Statistics, Chapter 1(cover the relevant parts in chapter 1){: .link-ext target=”_blank” }
Further ideas…
Most descriptive statistics can be calculated very easily using a spreadsheet. Once you have established the basic descriptive statistics, you could extend your analysis by investigating other topics in the Research Methods theme.