ABSTRACT
In this chapter, the author have described two categories of effect magnitude measures: measures of effect size and strength of association. An important advantage of a confidence interval is that it requires assumptions and data as a null hypothesis significance test, but the interval provides much more information. This is apparent when the people compare the coverage of confidence intervals in the convenience sample of eight introductory statistics books published between 1989 and 1991 with the coverage of seven books published between 2003 and 2005. The inclusion of more advanced statistical topics in introductory statistics books parallels the increasing availability of statistical packages. For example, the author introduce new statistics with a real-life example of the way the statistic is used in psychology. It is not easy to convince students that statistics is relevant to psychology.
