Do we all have to be privy to this? Henry M. Silvert Ph.D. Research Statistician The Conference Board 845 3rd. Avenue New York, NY 10022 Tel. No.: (212) 339-0438 Fax No.: (212) 836-3825
> -----Original Message----- > From: Dennis Leitner [SMTP:[EMAIL PROTECTED]] > Sent: Wednesday, December 05, 2001 12:24 PM > To: EdStat-l > Subject: Important notice about Final Exam on Thursday > > Dear 507ers, > I've graded (finally) HW6 and returned them to you. You all did > pretty well on it. As soon as I get permission from the student, I'll > send you an exemplary solution. > But the HW8's were not done well at all, especially part 8(b). It > appears that I did not make something clear. To use multiple regression > you need to code the independent variables: Gender has 2 level; so > there needs to be 1 coded vector. SES has 3 levels so you need 2 coded > vectors. And then there will be 2 coded vectors for the interaction. A > total of 5 vectors. So far so good. Most of you did that. But then to > test for the Gender Effect you need to get the R-squared (or SS) from a > FULL MODEL with all 5 vectors and a RESTRICTED MODEL leaving out the > Gender Variable (so only 4 vectors remain). And THEN you use THE F > formula (R-squared full - R-sqaured restricted etc) to calculate the F. > You cannot read the F from the printout because it is NOT over and > above. Also, for the SES effect you need to use the same FM with all 5 > vectors and leave out the 2 SES vectors and compute the F using THE > formula. > Most of you noticed that your answers in (b) were different than in > (a), but didn't figure out why. We have always emphasized the FM and > RM and how things not in the RM go into the error term. But you didn't > show me you knew this concept. > In part (c) you used the MR approach correctly (with FM and RM). > The answers in (c) should be slightly different than your answers in (a) > because the dataset is slightly different. > > So here's my question: What should we do about the concepts that > you should have learned for HW8? Should we postpone the final until > next week - both the WebCT part and the in-class part? > I really think we should talk about this tomorrow in class and have > a thorough review for both parts of the exam (the WebCT and the > in-class). > > So we need to vote. Send me an e-mail note by 6 pm today. In the > SUBJECT indicate when you want the Final (AS SCHEDULED - both parts on > Thursday 12/6 or NEXT WEEK - we can talk about this, but it will > probably have to be on Thursday 12/13). > I'd like to review tomorrow and have the exam next week. I feel you > would all do much better. But vote today. Put either "AS SCHEDULE" or > "NEXT WEEK" in the SUBJECT line. If you want, you could put your > rationale or explanation in the body of the note. The results will be > posted very soon after 6 pm so that you know whether there will be a > FINAL tomorrow or next week. If you get this note, contact your friends > in the class via phone (in case they haven't checked their e-mail) and > have them vote. One vote for each person will be counted. > > I'm sick about this. I want you all to do so well, but I didn't > make something clear. I'm leaving the country Saturday morning (12/15) > and I wanted to have this all done this week. But your education is > more important than my schedule. I'll grade the projects while I wait > for your votes to come in today. > > I'm sorry. > > Dennis > > P.S. I've rescored Quiz 9. Most of you will be pleased with the new > scores. > > > > ================================================================= > Instructions for joining and leaving this list and remarks about > the problem of INAPPROPRIATE MESSAGES are available at > http://jse.stat.ncsu.edu/ > ================================================================= ================================================================= Instructions for joining and leaving this list and remarks about the problem of INAPPROPRIATE MESSAGES are available at http://jse.stat.ncsu.edu/ =================================================================
