The important reason why everyone should feel good about themselves

here is the reason:

http://www.scientificamerican.com/article.cfm?id=the-psychology-of-social

Bayesian Calculator

Aha! I've been looking for this kind of stuff for a long time. Glad someone made it:

http://psych.fullerton.edu/mbirnbaum/bayes/BayesCalc.htm

Infinity in Python

There are only two constants in the Python math module: pi and e. However, it is often useful to have positive and negative infinities as well. After a bit googling, there is a rather interesting way to get these values:

For positive infinity, just do:

float('inf')


For negative infinity, guess what -- float('-inf')


Somehow I find it very amusing.

Aluminum Foil for Burritos

The three happiest things in life are: sleeping, eating, and urinating. Having said that, I want to point out that Mexican-food-wise, Chipotle is my favorite restaurant. I sincerely love their chicken burritos, perfect for either lunch or dinner.

Today is Halloween. Although I've never it officially advertised, Chipotle is said to give a free burrito to whoever dresses like one. I went to Chipotle this evening to enjoy my burrito, and to see how others attempt to get a free burrito. To my amazement, most people just put some aluminum foil around arms or heads! That costume is too cheap!

But it was fun anway. =)

TA Preferences

It's always easier to bitch about this world than to adulate it. Nevertheless, I'll try.

The most rewarding part about being a TA is leading the workshop session (see previous post). During the workshop, I got to know students in person. And once such face-to-face interaction emerges, those students are no longer of only statistical significance.

(For the ideas on statistical significance and individual significance, Steven Landsburg wrote a very good chapter in his book "More Sex is Safer Sex". You might want to read it.)

One student came to my office hour once and seemingly got a very satisfying response to her question. She came again. This kind of "returning customer" illustrates a simple trust that has been built between me and students -- that Ting explains problems well and that students recognize my work. The same with my workshop. I've noticed it is almost the same group of people that will come to my workshop session. And once a new member joins, she stays.

I have been against excessive use of complicated language in either learning or teaching. It annoys me that some people, for reasons that we all probably know, are particular fond of showing off knowledge in convoluted manners. When I explain problems to students, I always try to use the simplest language and a straight-forward logic to illustrate the problem. Learning is not just about acquiring a technical language, but more importantly, the correct way of thinking.

TA Bias/Preference

This year I have been assigned to be one of the two TAs (teaching assistant) for a statistics course offered by our department (http://www.bcs.rochester.edu). I am responsible for grading students' homework, exams, and offering a workshop session, where students can come and ask questions about homework problems. Additionally, I need to prepare keys to homework and/or exams every other week (rotating with the other TA).

This is the first time that I've been a TA. And as with all first-time experiences, I've become overly sensitive to all the interesting observations. Of all encounters with students, both enjoyable and annoying, one rule seems to be true: students have clear preferences/biases towards me, and that's probably due to the fact that I am an international student.

Students never turn homework into my mailbox. The mailboxes are ordered by last names in our department. And my last name, QIAN, looks strikingly weird since it breaks one important spelling/phonological rule of English -- Q is usually followed by U. Students may remember that my first name is Ting. But it may appear difficult to locate my mailbox by remembering my last name.

Relatively few students come to my workshop session. This is also interesting. I suppose there are two reasons: a practical one, and one, again, due to my non-American background. First, my workshop session is at 8pm in the evening, which might be party time for some people. Second, it is very natural for students to try to avoid non-American TAs, since bad accents do affect the quality of teaching. I personally have such preferences when I was an undergrad.

Students tend to argue with me, insisting that his/her answer is only "saying the same thing" as the correct key. Interestingly, some students assume that I can be easily fooled around by trying to confuse me verbally. The basic strategy is to 1) extract keywords from the key (which I prepared), 2) re-order the keywords and plug them into a sentence using a different structure, 3) show that this sentence is (almost) the same as his/her answer and asks for points back. On such occasions, I respond as follows: 1) your answer is mathematically equivalent to: (blablabla), and 2) the key is mathematically equivalent to: (yadayadayada). Bla is not yada. Therefore, you are still wrong.

In next blog, I'll write about the preferences.