Learning objectives aid revision by reminding you of the concepts you will have mastered in each chapter.

In this chapter you will discover:

• Statistical models
   
• Central tendency: the mode, median and mean
   
• Dispersion: the variance, standard deviation, and interquartile range
   
• Quartiles and percentiles
   
• Estimating model fit
   
• Deviance and the sum of squared errors
   
• Degrees of freedom
   
• Outliers