1 Measuring location

Measuring location has two components:

• gathering data about the quantity of interest

• determining a value to represent the location of the data.

The task of gathering appropriate data is somewhat problem-specific – general strategies are available, but exact details usually need to be decided for each problem. To determine the price of an electric kettle, for example, we would have to decide the size and type of kettle we’re interested in, where and when its purchased, and so forth. In contrast, choosing a value to summarise the location of a set of data is more straightforward. In this section, we will focus on the two most common measures of location: the median and the mean. The data gathered about the quantity of interest does not affect the way we calculate these location measures.