ABSTRACT
This chapter explains three important questions, when examining the relationship between two variables. The first is whether and to what extent changes or differences in the values of an independent variable are associated with changes or differences in the values of a dependent variable. The second question examines the direction and form of any association that might exist. The third considers the likelihood that any association observed among cases sampled from a larger population is in fact a characteristic of that population and not merely an artifact of the potentially unrepresentative sample. The chapter introduces some of the statistics that are most commonly used to answer these questions and explains when it is appropriate to use them and what they tell about relationships. A widely used coefficient of association for two nominal variables where one is treated as independent and the other dependent is lambda. The test of statistical significance for nominal variables is chi-square.
