Chapter 3: Representing and Analyzing Data with Measures. Center, position, spread.

This chapter focuses in the three types of measures that are most commonly used in descriptive statistics: the measures of center (aka central tendency), position (aka relative position) and spread (aka variability, dispersion, variation). We will also introduce the concept of outlier and resistance of a measure.

The measures of center intend to represent (preferably in a single value) the whole data set. The measures of position intend to show the position of particular values relative to the other values in the data set. The measures of spread intend to represent how disperse or diverse the data set is.

We will show that a measure of center shall always be complemented with a measure of spread. We will also see that each pair measure-of-center/measure-of-spread can be visualized easily in a particular type of graph.

In future chapters we will also study measures of strength o likelihood.

Handouts:

Chapter 3: Analyzing and Representing Data with Measures. Center.

Chapter 3: Analyzing and Representing Data with Measures. Relative Position.

Chapter 3: Analyzing and Representing Data with Measures. Spread.

The online lessons: