Monday, December 31, 2012

Parenting 26 months: For your entertainment, tonight's concert is . . .

This month T has been learning how to use his voice.  And he practices by singing. Unfortunately, he does not come with a volume control.  But he gets lots of points for singing with enthusiasm.

Some favorite performance pieces include Old MacDonald has a farm and Twinkle, Twinkle, Little Star.  But the absolute favorite is Da hai-guxiang.  He has been asking grandma (lao-lao) to sing this for him at naptime.  Now, he wants to do the singing.  And from watching videos he knows that a proper singer needs a microphone, so if he can get hold of any microphone shaped object (markers are the main standby) and an audience he bursts into song.

He also likes reading.  Now, part of the nighttime reading routine is we read a book, but he reads at least one.  Christmas saw the Who is coming to our house? as one he quickly learned most of the words to.  Other books that he reads in part include "Freddie Frog is Hungry",  "Little Pea," and "That's Not My Dinosaur!"   And then there are the books that he reads out loud in full.  "Brown Bear, Brown Bear, What do you see?" and "I am Sam"

My wife has been packing up older toys to give away.  He had a fun time going through the boxes playing with some of them, but he has never been all that serious about toys.  When his older cousin visited for Thanksgiving one of his first comments was that we did not have any toys (slight exaggeration, he is only four).  While he does play, we are far and away still his favorite playtime accessory (followed very closely by grandparents).

Sunday, December 30, 2012

Book review of Statistics in a Nutshell 2nd ed. by Sarah Boslaugh

Statistics in a NutshellStatistics in a Nutshell by Sarah Boslaugh
My rating: 4 of 5 stars

One of the biggest problems faced in teaching statistics is the gap between learning the methods to actually using them. Statistics classes that are based on learning formulas fail due to the disconnect between learning formulas and the reality that very rarely are these methods used by implementing the formulas that are so painstakingly taught. But learning statistics as a set of steps or functions in a computer package only gets a little further. The real goal should be what methods should be used and why. The how is almost secondary. Statistics in a Nutshell focuses on the what and the why. I would not use this to learn how to perform a technique or its formulas, but this is where to go to understanding how the various methods of statistical analysis should be used and their qualities. It is meant to be read, not just studied, and as such it holds a different place than other statistics texts.

When I first learned statistics, the focus was on learning formulas that calculated various values. But the problems I could work on were only toys, and it took so long that we did not get into much of understanding what we were dong. Now with readily available software packages, the temptation is to focus on the mechanics of implementing a procedure on a set of data and reading the computer output. But software documentation and even books that teach statistics fall into the trap of focusing on how a method works then applying it and not as much on why. Part of this is because of the pressure of having to cover topics, but the fact that the methods are presented in isolation, without their application context so it is rare to grapple with the question of how to know what needs to be done and instead the focus is on how to do it.

Statistics in a Nutshell is the other kind of book. I was taught that for computer programming for any language you wanted a book that focused on methods, but also a book that focused on morals, the why you use a language feature. This is the morals book for statistical programming. You read it, not to learn how to calculate statistical output or implement visualizations, but to think about what method or visualization is appropriate to help understand the data and environment and to communicate those truths to an audience.

Because of the expectation that any course that teaches statistics gives the students a toolkit, this would never be a good book for teaching a course. But in the real world, what is more important is that you understand what these statistical methods are and why you use one over the other. So for the data analyst or a student who needs an overview of everything this is ideal. It would also be ideal for someone who may not have the time to go into detailed study of statistical methods, but needs to interpret the results or work with statisticians and data analysts. This book will help interpret what you get and ask the right questions to both understand statistical results and perhaps point those who are doing the analysis in the right direction so that they are answering the right questions.

Note: I received a free electronic copy of Statistics in a Nutshell through the O'Reilly Press Bloggers program.

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Saturday, December 22, 2012

Engineers can read! A book review of Against the Gods by Peter Bernstein

Against the Gods: The Remarkable Story of RiskAgainst the Gods: The Remarkable Story of Risk by Peter L. Bernstein
My rating: 4 of 5 stars

One problem with the teaching of math and statistics as practiced in the U.S. is that it often seems like a series of topics that are sprung out of whole cloth with no context. Against the Gods has two parts: a history of how views of risk developed within western civilization and then a examination of the tools and (mis)use of risk managements in modern finance. In doing so it paints a picture of not only what the principles of probability and risk management are, but why they were developed and how they are used (and misused).

I had assigned this book as part of a course in decision analysis within an engineering department to a mix of upperclassmen and graduate students. Most found the first have to be fairly uninteresting. But the payoff came later as Bernstein tracked the growth of the development of probability to its application in insurance then to financial instruments in general By the end of the book we were discussing the purpose of modern financial instruments in terms of risk management using both modern examples and the 15th century patrons of renaissance explorers. And seeing how not understanding the principles and purposes behind the techniques leads to trouble, many of my students said the book gave a greater appreciation for the probability and statistics they have been learning.

And a gratifying note, in their report, many of the students stated that they did not read outside of their technical books, but after this experience they developed an appreciation for non-fiction and planned on looking for more such books to read in the years to come.

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Friday, December 21, 2012

Book Review: 21st Century C by Ben Klemens

21st Century C: C Tips from the New School21st Century C: C Tips from the New School by Ben Klemens
My rating: 4 of 5 stars

All engineering students take a one semester course fairly early in their education. My experience as a professor is that most of them promptly forget it and never make use of it again. I get alternately amused and discouraged at the lengths some of the students I work with go to avoid programming again. Because that one semester course teaches a programming language, but does not teach someone how to program. This book is meant to take someone through that step. It is sometimes hard to follow (my heavy programming in C was years ago) but it gets someone to where they can be productive.

When someone is referred to me an claims to have some programming background, I have learned to ask a simple question: have you programmed with libraries? I usually get a blank stare, and I know that this person may have taken a class, but cannot do anything useful. What this is how to make programming in C useful. So it builds in working with the various utilities that make C programming useful (I learned pkg-config and profiling with valgrind with this book. And before I used to be able to edit Makefiles but I would not try to write one from scratch) And, of course, working with C using some fairly useful libraries (if I am programming I am general pulling data from databases and using numerical methods, so I am rather pleased at the use of SQLite and GSL as example libraries).

The various tools are very useful. Programming without learning to use the various utilities such as debuggers, library managers, packaging, etc. is an exercise in frustration (and is how the standard introduction to programming course is set up).

Am I a convert? I still regard Python and R as my preferred environments, and I'm not swayed by his arguments that C is a "punk" language. I still find that all the little cruft such as pointers and their management something I'm glad to avoid. But I also regard one of the best features of Python and R the fact that I can dive into C when I need something fast and efficient. So being able to do this more effectively is good to improve my toolkit.

The book is not really for pure beginners. If you did not already have some background in C, you need to get that somewhere else. I got in trouble with some of the examples, so it helped that I have used many of these tools before (even if not all that effectively). It also is opinionated, presenting one way to do things. (of course, that is very useful to someone starting out, knowing one good way is better than having a dozen options in front of you when you don't know what is what). But it can be very good for someone who needs to go from "I have learned C" to "I know how to effectively use C."

Note: I received a free electronic copy of this book from the O'Reilly Bloggers program.

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Wednesday, December 19, 2012

Public transit: 2012 update

List of cities/metro areas that I have used public transit

Washington, DC
Chicago, IL
Boston, MA
Champaign-Urbana, IL
New York City, NY
Denver, CO
Vienna, Austria
London, United Kingdom
Singapore, Singapore
Bangkok, Thailand
Los Angelos, CA
San Francisco, CA
Seattle, WA
San Jose, CA
Portland, OR
Philadelphia, PA
Charlotte, NC
Montreal, QC
Phoenix, AZ
Berlin, DE

Sunday, December 09, 2012

Lessons observed from using cases in teaching decision analysis

I taught a course in Decision Models last semester. While there was a text, instead of relying on the text for the assignments, I used cases to provide practice in applying the concepts.

I chose two cases from the INFORMS Transactions on Education, Home Depot and the OVA1 case. In addition, I had them read a book "Against the Gods" by Bernstein, and a personal case. The class as a mix of undergraduate and graduate students. All of the undergraduates were US born while the graduate students were more varied in background including US born, Chinese, Indian, Turkish, and one Western European. A few had work experience.

The Home Depot case was a multi-attribute decision making case. I had the students form teams of two and take a point of view in the case: HomeDepot, competitor, the local government, or local residents. While the case writers used one method, I had them structure according to SMART, which is what was used in out textbook and the class. Some notes. The students often had trouble staying in a point of view. This led to some strange arguments during the course of the case report. Also it made the assessment of values difficult for the students, as observed in their discussions and the values they assigned to attributes. Noone had background in the issue, except for one student who witnessed a similar debate in his hometown. They found assigning numbers to values difficult, But one result that I pointed out, also noted by the case writers, was they were remarkably in agreement in their final recommendations, even though their choices of. numbers varied wildly. As noted in the book and by the case writers, this was one of the justifications for the value of structured decision analysis methods in a highly subjective environment. I think that this exercise gave the course validity.

We also covered the eventual outcome. As the case writers expected, they generally came to the same conclusions as the decision in real life. But the eventual outcome s not very good, and in real life it is being revisited, so we could talk about if the decision was good even if the outcome was not as good as hoped for.

The OVA1 case was on medical decision making, and teams could be the doctor, the patient, or an insurance company. There was one person considering medical school in the course, This was used as an exercise in developing decision trees and assigning utility in the face of uncertainty. in addition, this was before they covered the value of information, so they essentially, they were developing the techniques of determining the value of information as they went along. They did much better with keeping with their assigned role this time around. And it took work, but they figured out the expected value of information method, which made teaching it later very easy. Also, the case got across the idea that decisions look very different when looking over a large number of instances (doctor and insurance company) compared to when you looked at a sample of one (patient).

The real question is the use of cases instead of homework. In an engineering department, this would naturally be one of the less quantitative courses. However, I presented it as an integrative course, meaning that the other courses teach methodology that are used to support decisions. Even with the case that was supposed to be based on a personal issue (I gave them some leeway by saying that it could be based on something or someone they personally know instead of just themselves)they commented on how hard it was to find data or determine utility in a quantifiable form. I think that presenting this in the form of cases made them work harder at it and gave them a deeper understanding than if I had them do a homework questions from the book where the numbers were given and they did not have to think about where they came from. I had many people comment in their reports that this class was making them think about many issues differently. (especially the personal case, where most of them even thought to include such considerations of their romantic relationships in their evaluation of decisions.)

Sunday, December 02, 2012

Parenting 25 months: I can do it

Here is a drum to work with by LugerLA
Here is a drum to work with, a photo by LugerLA on Flickr.
Highlight of the month was Thanksgiving. We hosted my sisters, along with my brother-in-law and nephew. It made for a crowded holiday. It was also a lot of fun as my nephew got to be the big cousin again and we went around to the places we like to play. In particular, we took everyone to the Carnegie Museum of Natural History, where T is a frequent and experienced visitor.

The major development this month is a lot more talking. Like most toddlers, it is mostly repetition. And he has taken advantage of many sources of repetition. In addition to the four of us (two of us + my in-laws) he draws from videos but especially books and iphone apps. Especially the books and apps, because of the repetition. We have been surprised by the vocabulary he has picked up that we could find no source except the iphone apps that he likes to play with.

His favorite books are the Little Pea/Hoot/Pig series by Amy Rosenthal. Actually, we let him do the talking when it comes time to read. He does a pretty good job of getting most of it, with the skipping of words declining weekly. What is most amusing is when he is pretty sure what is happening, but does not know all the words, so he improvises. We know what he means :-)

His newest catch phase comes from Potty by Leslie Patricelli. At the end, after a successful potty engagement, the toddler says "I did it!" Somehow, T has also learned "I can do it" along the way, and has started using it at any reasonable opportunity. There are worse phrases a 2 year old can learn, so we don't mind this one.