Tuesday, April 27, 2010

My latest review of "Joy of Thinking: The Beauty and Power of Classical Mathematical Ideas" from The Teaching Company

This review is also here: http://www.teach12.com/ttcx/CourseDescLong2.aspx?cid=1423


3 out of 5 stars.

A little disjointed and need to be faster
Date: April 25, 2010

"Although this course has some interesting insights and examples, I only give it a three star rating.
Here are some insights and examples from the course that I found interesting:
1. Fibonacci patterns in nature: Pineapples, cone flower and daisy.
2. The existence of 5 platonic solids (and no more than 5).
3. The representation of fourth dimension in the third dimension.
4. Probability trivia: Door number 2 or 3 --> contemplating extreme value & how our intuition may not be accurate.
5. Non-transitive dice.
6. St Peterburg's paradox - how an infinite expected value may not mean that it's a good idea to bet any large $ amount.
7. Experiment with 2 decks of cards - withdrawing each card simultaneously and figuring out the probability we find the exact same card in the same sequence, and
8. The birthday probability trivia.

But why the three star rating? Several reasons:

a. Too slow & not enough insights per lecture: I define whether a course is good or not from how many new, insightful ideas I can learn from each lecture. This one here doesn't provide as many new, insightful ideas as it could have. In comparison, the course "The Art and Craft of Mathematical Problem Solving" by Prof Paul Zeits (which I have also reviewed) have many new insightful ('AHA') ideas packed (too heavily in fact! - I had to 'pause' a lot) into each lecture. I recommend faster delivery for most of the lectures in this course.

b. The lectures are somewhat disjointed / too random: e.g., talking about Mobius Band and Klein Bottle --> so what? how does it link to the rest of the lectures? or how does it link to the 'geometry' section? what's the implication to the real world?

c. Some typo (typing error): For e.g., in the DVD in lecture 20, the probability of winning the car by switching the first guess (in a 1 billion door example) is written on the DVD as 1 / 999,999,999 --> this is wrong! (the lecturer said it correctly - but it was written wrongly).

d. I feel Prof Ed Burger is better than Prof Michael Starbird in explaining the lectures' examples, although both are enthusiastic.

e. Awkward camera perspectives/angles - for instance, when Prof Michael Starbird was explaining the cones and ellipses, the camera moved from the schematics to the closed-up real example (i.e., cone held by Prof Starbird) too much that it confused me. I figured out the insight myself through my own experimentation but this could have been explained clearer by just having the camera sticking to the schematics only.

f. Not enough mathematics. For instance, in lecture 22 (on randomness), Prof Ed Burger noted that the probability that the needle in Buffon's needle will cross a line is exactly equal to 2 / pi. But how was this answer arrived at?? Prof Paul Zeits, in contrast, will go through this in detail.
Another example is: In lecture 23, there's a very interesting probability problem where Prof Ed Burger talked about two decks of cards and withdrawing the cards simultaneously. He said that the probability of flipping over two of the exact same cards at the same time = two thirds (66.7%). But how did he arrive at this conclusion? Out of curiosity, I googled it and couldn't find it. So I calculated this myself and found that the answer is actually 63.9% (but I could be wrong). I wish Prof Burger explained this more!

g. Need answers to the questions at the back.

h. Advice/life lessons too vague and basic, and most can be grouped together."

Friday, April 16, 2010

My latest review: "The Art and Craft of Mathematical Problem Solving" (from The Teaching Company)

Here is my latest review of the course: "The Art and Craft of Mathematical Problem Solving" by Professor Paul Zeits from The Teaching Course. I have posted my review here as well:http://www.teach12.com/ttcx/coursedesclong2.aspx?cid=1483

Here it is below:

Fantastic topics and presentation
Date: April 10, 2010

"Around two lectures into this course, I couldn't help but saying to myself "WOW". This course is fantastic for several reasons:
  1. It uses plenty of pictures, animations and graphs. This really helped the understandings of the problems and their solutions. This is my fifth or sixth TTC course, and I really love the presentation of this course (through the use of the animations, pictures etc.) compared to the DVD versions of the other courses I have seen (which relied too much on the lecturers' verbal commentaries).

  2. Every lecture always has at least one problem to be solved - i.e., practical.

  3. Prof Zeits also almost always explains WHY the problems are solved in such ways, rather than just the HOWs.

  4. Some of the mathematical problems are very interesting and fun.
Overall though, most parts of this course are quite (mathematically) hard-core and require mastery of at least most of high school geometry, algebra, trigonometry and calculus to fully appreciate the courses' nuances. I have loved maths from a very young age, and there were around 3 - 5% of the problems/examples i did not fully get.

One recommendation I would like to make to Prof Zeits and TTC is that I noticed small / a few typos in the notes as well as in the written texts on the DVD, which occurred (I noticed) around where the problem's climax is at! (which could get annoying). But these are very minor in frequency. For instance, on page 27 of the course guidebook, point I.B.3 should end with "8Tn + 1" instead of "8Tn".

Personally, I loved the following problems (& the strategies and tactics to solve them) - not in any order:
  • The pill problem (in lecture 1).

  • "Determine, with proof, the largest number that is the product of positive integers whose sum is 1976" - using 2s and 3s - amazing! (and the importance of e) (in lecture 16).

  • The pigeonhole (and intermediate pigeonhole) tactics (in lecture 14). I think it has great applications - for instance, problem 2 on page 60 of guidebook.

  • Handshake problem (in lecture 10) - contemplate extreme values.

  • Wythoff's Nim or "puppies and kittens" problem (in lecture 9) - solved by plotting positions and contemplating symmetries.

  • And lastly, the problem in lecture 20: "What is the probability that a randomly chosen number in Pascal's triangle is even?" I love the process of answering this and the final patterns and answer!
Overall, this is a superb superb course and I highly recommend it, but only for the hard-core math enthusiasts."