Post-Exam Update:
I later noticed, after the exam had started that there was a typo in the binary logit question. The coeff of income^2 was shown as -.088 instead of -0.88. Hence, the predicted probabilities of channel watched for all 3 cases (min, max and mean profile of respondents) would now come up as 1. Folks who show the expression and calculations will get full credit for this problem.
A related Q regarding the DTH caselet. There are many possible assumptions you could make and from each, a different research design might flow. As long as you've stated clearly your assumptions and the research design that follows is logically consistent with your assumptions, you are OK.
Hope that clarifies.
Sudhir
Update:
Another thing I might as well clarify: - regarding the quant portion - only interpretation of a model and its associated tables will be asked for.
Even there, only those tables that we explicitly have discussed in class, not merely shown but discussed, will be important from an exam viewpoint.
Sudhir
Am getting quite a few Qs regarding this. A wrote in just now:
Sudhir
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Got this just now:
Hi all,
Was asked yesterday about this and might as well share with the whole class.
Q was that in the factor analysis homework, what to do if the factor solution with eigenvals>1 is still showing cumulative variance explained of <60%?
Well, if the % is in the mid to late 50s, just go with it.
If not, it would seem like the factor solution is not doing a great job of explaining variance in the input variables. This is presumably because at least some variables are not well correlated with the others and are hence weakening the factor solution.
To ID such variables, look either at the correlation tables or at the communlaities table. The variables that show least correlation with others should progressively be removed and factor anbalysis re-conducted at each step till the 60% criterion is met.
If a variable loads entirely on its own factor, drop that factor and use that variable as-is in downstream analysis.
Hope that clarifies. Any more such Qs and I shall share it here.
Sudhir
I later noticed, after the exam had started that there was a typo in the binary logit question. The coeff of income^2 was shown as -.088 instead of -0.88. Hence, the predicted probabilities of channel watched for all 3 cases (min, max and mean profile of respondents) would now come up as 1. Folks who show the expression and calculations will get full credit for this problem.
A related Q regarding the DTH caselet. There are many possible assumptions you could make and from each, a different research design might flow. As long as you've stated clearly your assumptions and the research design that follows is logically consistent with your assumptions, you are OK.
Hope that clarifies.
Sudhir
Update:
Another thing I might as well clarify: - regarding the quant portion - only interpretation of a model and its associated tables will be asked for.
Even there, only those tables that we explicitly have discussed in class, not merely shown but discussed, will be important from an exam viewpoint.
Sudhir
Am getting quite a few Qs regarding this. A wrote in just now:
Hi Chandana,My response:
Need a quick clarification. For this home work questions 1,2,3 and 4 are mandatory and 5,6,7 are optional. Is that right ?
Regards,
A
Sudhir
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Got this just now:
Professor,My response:
When I mailed you today morning, I had high aspirations of finishing my studies and then meeting you for a quick review. Unfortunately, I just finished going through Session 4 hand out. My sincere apologies but I guess I will have to cancel this appointment…and give the slot to a better prepared student…!!
Thanks,
K
That's OK. Drop by anyway. I expected I'd be busy during these office hrs but am (pleasantly) surprised. Seems folks have on average understood the material well and don't need additional office hrs now.----------------------------------------------------------------
Besides, anyway, the exam is not designed to be troublesome. I wouldn't worry overmuch if I were you.
Sudhir
Hi all,
Was asked yesterday about this and might as well share with the whole class.
Q was that in the factor analysis homework, what to do if the factor solution with eigenvals>1 is still showing cumulative variance explained of <60%?
Well, if the % is in the mid to late 50s, just go with it.
If not, it would seem like the factor solution is not doing a great job of explaining variance in the input variables. This is presumably because at least some variables are not well correlated with the others and are hence weakening the factor solution.
To ID such variables, look either at the correlation tables or at the communlaities table. The variables that show least correlation with others should progressively be removed and factor anbalysis re-conducted at each step till the 60% criterion is met.
If a variable loads entirely on its own factor, drop that factor and use that variable as-is in downstream analysis.
Hope that clarifies. Any more such Qs and I shall share it here.
Sudhir
Hi A,Yes, only Q1-4 are mandatory. Rest are optional in session 9 HW.
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