ABSTRACT
In this chapter you will:
Learn how to estimate the population variance from the value computed for the sample.
Be introduced to the concept of degrees of freedom.
Learn about the F distribution.
Learn how to determine whether the proportion of variance accounted for in a sample by a single predictor is statistically significant.
Learn how to do a one-way analysis of variance with two independent groups.
In chapter 5 you learned how to compute the variance for a sample of scores, and in the last chapter you learned how a portion of that sample variance could be accounted for, using the best prediction equation (in the least-squares sense) and values for a single independent variable. These topics belong to the realm of descriptive statistics. In this chapter, on the other hand, we discuss ways of moving beyond the sample, inferring facts and relations that probably characterize the population from which the sample was drawn. Thus the material presented here, like that in chapter 7, concerns inferential statistics.