Friday, May 28, 2010

Extension Results

At the start of semester, at one point I had 48 people signed up for my extension Algorithms and Data Structures course, which I said from day one would not last.  (The extension class is for Distance Education students, offered by Harvard's Division of Continuing Education;  students see recorded versions of the Harvard class lectures made available online, and I run the class very much like the Harvard class.)  17 made it through to get final grades.  That's well within the normal range.

My reviews from the extension school have generally, over the years, been satisfactory.  As I usually have minimal personal interaction with the students, I've never expected great reviews.  Strangely, for the last two years, while my teaching review numbers for the regular Harvard class have significantly declined (due to a vocal minority that appears to not enjoy the class), the numbers for the extension class have significantly risen.  Perhaps I should be concluding that I'm better on camera than in person?

Really, I'm at a loss to explain.  Obviously, the extension reviews are from self-selected survivors, so they're more likely to appreciate the class.  In the regular class, I notice that the poor reviews seem to come almost exclusively from those who are taking the class because it is (almost, but not really) a requirement for being a CS major -- hence, possibly, from people who don't really want to be there in the first place.  I might think extension students have lower expectations, in terms of grades.  For administrative reasons they really want to get at least a B in my class, and I think they're prepped to understand coming in that that's a difficult goal.  I should point out that most -- indeed, nearly all -- of the 17 left at the end got a B or higher.  Most also come in quite aware of the gaps in their background and work very hard to make up for them.

However, none of these things seem to explain the delta over previous years, and in particular the difference in direction in the delta between these two groups of students.  Go figure.

In any case, the extension students from CS 124 this semester should be very proud of themselves.  I believe my class is one of the more challenging undergraduate Algorithms and Data Structures classes at any university -- extension or otherwise.  Many (most?) of these students have jobs, families, and other responsibilities that make taking any class extremely difficult.  They should know that I'm impressed by them, and I hope my class turns out to be a useful experience for them.


Sindhu CS said...

I am Sindhu Chenjeri. I am student from Harvard Extension and took the CSCI E-124 course this spring.
This is my heart felt appreciation for the course. The material and the teaching was simply superb.

I am able to apply some of these in my job too :-)

It was really a pleasure to watch your lecture, the only regret that its only online. I would have loved to attend in person.

I hope in future I get to hear more such lectures from you.

Unknown said...

Dear prof. Mitzenmacher,
Your course gave me much complement theory to what I already did in practice. Now I have a broader view and more important - for the first time I have an insight to my profession as a science. I'm looking forward for more knowledge.
Thank you,
Anton Kostov

Richard said...


I'm touched by your words about extension students.

For the record, I took your class during a summer session (against the advice of Dean Leitner) because I needed a distance course to complete a field of study in Comp. Sci. for my ALB. (HES doesn't really do majors/concentrations; that's another argument for another time)

I can honestly say that your class was the most difficult one I took at HES, bar none. It was also the most useful and critical part of my education. I earned a B- (I think I could have made it a B during the regular term) but I was happy to have spent the time on the course.

I've been appreciative of the support the CS faculty has shown to HES students. Many of us started off in college but left to pursue a career when it seemed more fruitful and interesting than academia. As you know, it's significantly more difficult to return once you've accumulated some responsibilities in life.

In any case, the one thing that caused me the most grief was dynamic programming. I'm sure this isn't news to you, but maybe more attention to presenting DP in a more measured way would be helpful. I lost big points on DP and that really, really smarted.

Michael Mitzenmacher said...

Thanks all of you for your comments!

I'll advertise I'm doing my "grad course" through extension next year -- feel free to sign up or spread the word.

Richard -- I agree with you -- DP causes the most grief of any topic in the class. I'm thinking of changing up that lecture, and adding some more time for it. It's always been hard, but it seems people are struggling even more with it the last few years.

Jason said...

I was also one of the survivors this Spring. Like Anton, I believe your course provided a key missing link in my education by connecting theory with practice. I have had many more practical programming courses or more mathematical courses, courses that focused on implementation of data structures, etc. Your course was unique in that it really helped me to understand how the field is being advanced. For example, your gave the foundation necessary to read and comprehend something like your Carousel paper, albeit with references to understand more than a few terms/concepts simply given as “well-known.” :) My professional background already has me understanding all too well the problem of logging all the hosts involved in a coordinated botnet attack or worm proliferation. Now for the first time I can see how the theoretical building blocks are arranged to propose a solution to a problem that is very real and practical.

Know that your Algorithms course has a reputation among extension students for being extremely challenging, but equally rewarding. I know one who plans to take your course for no credit after graduating just because of this reputation. (I have argued, only half joking, that this is a cop out & failure to take the course on the chin in GPA like the rest of us.) If I was not so sure that you meant none, I could almost take offense to your comment about lower grade expectations. I heard many of the B students you mentioned comment before grades were handed out that your course was well worthwhile, even if it would not count towards their admission into a degree program because the grade was below a B. Personally, the B I received in your course means more to me than the half dozen A's I've received so far in Extension (five of them in CS to speak to theories put forth in your grade inflation post) and pile of 4.0's I've received at other schools. I, like many peers in Extension with whom I have had the pleasure to become acquainted, was attracted to Harvard Extension by the challenge in the first place. My expectation for grades has never been lower, rather, I have respect for the grade in spite of it being below my expectations. This is both because I see it as one of the more fair assessments I have received in grade form and because I have now joined the ranks of those who know just how rigorous your course is and what the grade really means. I also appreciate that you made the course a worthwhile investment of my money and, most importantly, my time.

It is also worth noting that rigorous courses like yours often are not the best fit for the extension format. There is a feeling of isolation associated with the online only format and I think that plays into the drop rate with harder courses. We did not have the opportunity to work in groups for programming assignments, even as we watched you recommend group work with enthusiasm to the day class. Even the chance to commiserate with peers briefly on the way in and out of class was a desperately missed psychological aid. I myself was a drop last year when I found (unlike every other course I've taken that came with a warning label) your course actually is difficult and it did not make sense for me to continue in the midst of buying a house, moving and traveling for work. It was nice to see you support those students who did have to drop after the refund deadline this semester by advertising your willingness to write a letter on their behalf to petition for a refund. I wonder how many of them will end up like myself and come back at a future date, better prepared then go on to be successful in the course.

In all this I am not complaining, but trying to share a perspective. For all these reasons are some of what leads many professors to not offer their courses via Extension. I thank you for making your course available in spite of these challenges. I hope you offer more of your courses in the future and encourage your peers to do the same. Your efforts are certainly appreciated!