Regression with a Categorical Independent Variable (UPDATED!!!)

Hi everyone,

Since I noticed that some of you will have a quiz tomorrow without getting your HW4 back, I would like to provide some feedback which may help your quiz tomorrow.

If you can still remember that you were asked to calculate group mean for different levels (age group) of an independent variable, some of you might have rounded off the unstandardized betas before plugging them into the formula that help you figure out the group mean. I suggest you not to round off unstandardized betas before you plug them into the formula in order to get a more accurate group means. For example, you can see that you got an unstandardized beta (4.5678) on the coefficient table (spss output), plug in 4.5678 instead of 4.57 into the equation to get a more accurate group mean.

Hope this helps!

All the best with the quiz tomorrow or Thursday!! :)

UPDATE-->
I would like to add something too.

For the HW4 question 3 asking you about whether both first session and number of session significantly predict DV or not. You need to look at the significance level in the coefficient table (spss output), but not assessing the significance level by looking at R square only. The significance level is determined by whether the beta of the IV reaches statistical significance or not.

I know this is late at night... I wish I could have put this up earlier.

I'm praying for you guys...