1. If you have not done so already, conduct the multiple regression testing the interaction of TV and Ability on Achievement conducted earlier in this chapter. Compare your results to mine. Make sure...

1. If you have not done so already, conduct the multiple regression testing the interaction of TV and Ability on Achievement conducted earlier in this chapter. Compare your results to mine. Make sure you are able to correctly center the variables and create the interaction term. Try the different methods for graphing the interaction. The data are on the Web site (tzkeith.com) (“tv ability interact2.sav,” “tvability interact2.xls,” and “tv_abil.txt”).

2. Conduct a similar analysis using the NELS data. Try using F1S45A as the measure of time spent watching TV and a mean of the 10th-grade test scores (F1TxRStd, F1TxMStd, F1TxSStd, F1TxHStd) as the outcome. Because NELS did not include measures of ability, test the interaction of TV and Previous Achievement (ByTests). Also control for base year SES (BySES). Is the interaction statistically significant? Graph the interaction (or the lack of an interaction). How do you account for the differences between these findings and those from Exercise 1?