Top ten mistakes made by students in OR 389
- Too many formulas. You may think: well, these guys (ie. the profs) like formulas, and math,
after all, that is why they are on the faculty... so let's put lots of formulas, theorems, and lemmas.
WRONG. We may like formulas, but nobody likes other peoples' formulas.
The author of a famous popular physics book, Stephen Hawking (the book is "A brief history of time") once got
the following comment from his publisher: every time you put a formula into the text, you should multiply
the audience by 0.5. With some changes, this is true for any talk. A one hour talk should not contain
more than 5-10 equations! After that, the audience will simply "pass out", no matter how smart, or mathematically
sophisticated they are.
SUMMARY: Put only the really important formulas into the talk, and explain them very, very thoroughly.
- Not well understood notation. You may think: well, I understood this x_ijkl thing 80% at least...
that should be enough. After all, nobody will want to know more than that, and I can always make up an explanation
for the remaining 20%.
WRONG. Sometimes you may get away with this, but do not count on the laziness of the audience.
Seeing a confused speaker is pretty embarrassing, being one is probably worse. You will have to give
professional presentations during your career, be that academia, or industry. So, to prepare you for that,
we (the profs) will give you a hard time, if you don't seem to be 100% sure, what you are talking about.
This is in your best interest: after all, the more you sweat in peace, the less you bleed in war.
SUMMARY: Every single formula, notation you give, you should understand it 100% ! Also, you should be able
to explain it: if you cannot explain it, then you never really understood it yourself in the first place.
- Too few examples. To gain insight into the problem, you should always work out some
trivial special cases. For instance, in the airline reliability talk by Niraj, one could wonder:
suppose we have two airlines, one is on time 50% of the time, the other 60% of the time.
As time goes to infinity (ie. take the i'th month, and let i go to infinity), will all
the customers switch to the better airline? Your intuition says yes. Do the formulas
say the same? That is, you should work out the formulas that give the number of passengers
at the two airlines in the i'th month, and check that indeed the number of passengers at the worse
airline goes to zero. You may want to actually give the example in the talk, or you may not.
Even if you don't, working it out just for yourself will help you to understand the material better, and that
can only help in the talk.
SUMMARY: Give examples, and explain them very well (of course!).