Steve Kass

I’m changing web hosting providers, so things will probably be a mess for at least a few days.

The Federal tax filing deadline for regular 2006 tax returns is Tuesday, April 17, 2007, not Monday, April 16, 2007. Same for the state deadline here in New Jersey, and maybe your state, too. Why? Here’s the IRS’s answer:

Why are taxpayers getting extra time to file and pay?

Taxpayers will have extra time to file and pay because April 15 falls on a Sunday in 2007, and the following day, Monday, April 16, is Emancipation Day, a legal holiday in the District of Columbia.

By law, filing and payment deadlines that fall on a Saturday, Sunday or legal holiday are timely satisfied if met on the next business day. Under a federal statute enacted decades ago, holidays observed in the District of Columbia have an impact nationwide, not just in D.C. Under recently enacted city legislation, April 16 is a holiday in the District of Columbia. The IRS recently became aware of the intersection of the national filing day and the local observance of the new Emancipation Day holiday after most forms and publications for the current tax filing season went to print.

Individuals in the District of Columbia, as well as in six eastern states, already had an April 17 filing date prior to this announcement because they are served by an IRS processing facility in Massachusetts, where Patriots Day will be observed on April 16. These individuals are still required to file on April 17.

[link] IRS Q and A page about the April 17 deadline.

Check it out here. This is a heck of a lot easier than the WordPress editor.

A colleague recently drew my attention to this CNN.com article, titled “Confident students do worse in math; bad news for U.S.”

It’s interesting, I guess, but the analysis is flawed.

The article reports the results of a Brookings Institute study based on the 2003 Trends in International Science and Mathematics Study (TIMSS).

It’s the culture, stupid.

Where to start? First off, the countries with the best average math scores were East Asian countries. That confirms other studies and general perceptions, and it didn’t surprise anyone. Obviously, then, anything that correlates with East Asianness (straightness of hair, size of epicanthal folds, or facility in Chinese or Japanese) will also correlate with math scores when East Asian country-wide averages are compared with other country averages. One trait that correlates with East Asianness is self-effacement. Self-effacement tends to be highly valued in countries like Taiwan and Japan, but praising one’s self is not, and there was a survey question that measured self-effacement: “How strongly do you agree with the statement ‘I usually do well in mathematics.’”

It shouldn’t have surprised anyone that students in East Asian countries were less likely to answer “strongly agree” when asked how much they agree with the statement “I usually do well in mathematics,” so it shouldn’t have surprised anyone that country-wide averages on this survey question correlated (inversely) with mathematical ability. The correlation is simply explained by culture and the known difference between countries in mathematical ability.

Hurting the chances for a fair airing in the press (if there is ever any chance), the Brookings analysts repeatedly confuse expressed self-confidence with true self-confidence, too: “In the TIMSS data, when one looks at the math scores of students within each country, those who express confidence in their own math abilities do indeed score higher than those lacking in confidence,” and “The world’s most confident eighth graders are found…”, and “students in [East Asian] countries do not believe that they do very well in math.” Combine this with the fact that while the Brookings folks do notice the culture question, they dance around it enough to let reporters to come away with conclusions that are a good six fallacious leaps away from the data and statistics, like “Happy, confident students do worse in math” headlining an article by Association Press education writer Ben Feller. Nothing in the data suggests that confidence in mathematical ability is inversely related to actual mathematical ability at the level of individuals, but the headline gives that impression, strongly.

Another problem with the study is that it commits the ecological fallacy. It speculates about how confidence and ability are related in individual students from country-wide aggregate data, and the press drag these wrong conclusions in the wrong direction. The aggregate data is screwy to begin with, given the very strange list of countries surveyed. Many have small populations: Jordan, Israel, Bahrain, Cyprus, Latvia, the Palestinian Authority, Moldova, Lithuania, Scotland, Norway, Flemish Belgium, Botswana, Macedonia, and Serbia, and a few have large populations: Russian Federation, Japan, Indonesia, Malaysia, the United States, and the Philippines, but each country’s average mathematics score counted the same in the statistical analysis to which the press is paying the most attention. The country list was hardly comprehensive, either. Chile was the only American country on the list besides the U.S.

A regression weighted by population would have been a little better, but drawing any conclusions about individual students from country-wide averages is invalid. Here are a couple of good articles about this fallacy: (link) (link).

The TIMSS data contains plenty of useful information to support a conclusion opposite to the one reported. The data showed that all other things being equal (that is, among students within any one individual country) higher student confidence (which, ceteris paribus, should now correlate with expressed confidence) in math ability tended to be associated with higher math ability. The Brookings folks observed this, and they called it paradoxical: “So an interesting paradox emerges from the international data on student confidence and achievement. The relationships are the opposite depending on whether within-nation or between-nation data are examined.”

When Brookings writes “The international evidence makes at least a prima facie case that self-confidence, liking the subject, and relevance are not essential for mastering mathematics at high levels,” it’s easy to think they are suggesting that the ecological fallacy analysis is telling us something, and they are diminishing the different conclusions supported by the ceteris paribus analysis. And the reporters take the hook. I wonder how good the press corps and the Brookings researchers think they are at statistics.

This is huge. To call it one for the history books is an understatement. (Links)

[Followup to this post.] Julie from Bolthouse farms emailed me today, saying that “The unexplained carbohydrate is coming from the natural flavor added to this product. We are and will remain in compliance with all applicable regulations regarding our products.”

In my opinion, it’s misleading, if not just plain wrong, to advertise a product as having “No Added Sugars” (as Bolthouse Farms does here) when it contains unspecified ingredients (“natural flavor”) that add 15-20 grams of sugar–the amount in 3-4 teaspoons of table sugar. It seems to me especially at odds with what Julie expressed as the company’s goal: “to provide our customers with healthy, nutritious and good-tasting products designed to provide genuine and legitimate options for those individuals wishing to improve or enhance the overall quality of their diets.”

For the record, the FDA, which regulates food labeling, defines the term natural flavor as follows (link):

The term natural flavor or natural flavoring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional.

Groundbreaking when it was published in 1955, the classic book “A Million Random Digits with 100,000 Normal Deviates” has been republished electronically by the RAND corporation with permission “to duplicate this electronic document for personal use only, as long as it is unaltered and complete.” Books like these were a staple of statistical research in the mid-20th century, and this particular one was highly revered.

Nowadays, there are better sources of random numbers, such as HotBits, and there are many ways to generate pseudorandom numbers, which are not random, but have many of the properties of random number and are useful for many purposes.

I hope it’s not a violation of the copyright for me to provide instructions on how to use SQL to load the book’s content in its published format (or any identically-formatted list) into a SQL table that can be queried for random (not pseudorandom) sequences of numbers. The script uses a few of SQL Server 2005’s new features, including the BULK rowset provider for text files, some of the new analytic functions, and TOP with a variable. You’ll also need a table-valued function called Numbers(), like the one in my previous SQL post.

The RAND book is available here, and my script works for the support file “Datafile: A Million Random Digits,” available for download here. The SQL Server 2005 script below assumes you’ve downloaded this file and unzipped it to C:\\RAND\\MillionDigits.txt.

The beginning of the file looks like this

00000   10097 32533  76520 13586  34673 54876  80959 09117  39292 74945
00001   37542 04805  64894 74296  24805 24037  20636 10402  00822 91665
00002   08422 68953  19645 09303  23209 02560  15953 34764  35080 33606
00003   99019 02529  09376 70715  38311 31165  88676 74397  04436 27659
00004   12807 99970  80157 36147  64032 36653  98951 16877  12171 76833
00005   66065 74717  34072 76850  36697 36170  65813 39885  11199 29170
00006   31060 10805  45571 82406  35303 42614  86799 07439  23403 09732
00007   85269 77602  02051 65692  68665 74818  73053 85247  18623 88579
00008   63573 32135  05325 47048  90553 57548  28468 28709  83491 25624
00009   73796 45753  03529 64778  35808 34282  60935 20344  35273 88435

Unix-style newlines (0x0A) are used, and the million digits are organized into 20,000 five-digit integers with leading zeroes, so the script will import the file into a table of 20,000 five-digit numbers (as char(5) data with leading zeroes). Here’s the script:   (more…)

Yesterday was my scheduled departure date for a two-week planning trip for a May/June 2007 Drew International Semester to Beijing, Xi’an, and Dunhuang. Boarding pass in hand, I arrived at gate C123 for the nonstop flight to Beijing. The flight was oversold, perhaps because it would arrive in China on a lucky day, 8/8, and the gate agent called for volunteers to take the next day’s flight. I don’t pretend to believe in fate, but I couldn’t help feeling some validation of the ambivalence I’d had about the timing of this trip, and I volunteered. Continental needed my seat, and I collected a boarding pass for today’s flight, two $350 travel vouchers, a taxi voucher to get home, and another day to consider postponing my trip.

I cancelled my itinerary last night, and I’ll make new plans to go in December or January. This month, I’ll spend a week in Phoenix with my mom instead of two weeks in China away from her. Dad died in June, and spending time with mom (and dad’s spirit) can’t wait until winter as easily as the trip to China can.

[There is a followup to this post here.]

Perfectly Protein® Mocha Cappuccino with Whey Protein (PP®MCwWP for short) is one of Wm. Bolthouse Farms’s newest beverage products, and I tried one recently. It wasn’t bad, but it wasn’t very memorable either, at least not as a drink. It was interesting to read though, and I’m convinced that either the ingredients or the nutrition facts are wrong. As of this writing, the ingredients listed here on bolthouse.com match what was on the bottle I saw: Mocha Cappuccino (Low Fat Milk, 100% Arabica Coffee, Natural Flavors, Vanilla Extract (Madagascar),Cocoa), Milk Whey Protein, Potassium Diphosphate, Apple Juice, Pectin, Carrageenan, Calcium (Tricalcium Phosphate), Vitamin C (Ascorbic Acid), Magnesium (Magnesium Oxide), Vitamin B6 (Pyridoxine Hydrochloride), Zinc (Zinc Sulfate), Iron (Ferrous Lactate), Vitamin B12 (Cyanocobalamin). It tasted sweet to me–sweeter than milk with a splash of apple juice would probably be. The Nutrition Facts made more sense: 28 grams of sugar in 8 ounces.

Where do those 28 grams of sugar come from? I called Bolthouse to ask, saying that the ingredients didn’t seem to add up to 28 grams of sugar. Julie in Consumer Relations emailed me back to say that PP®MCwWP is naturally sweetened by the apple juice. There is no sugar added.”

Let’s figure it out. (more…)

This morning, I rode New Jersey Transit to Newark International Airport, which is about 12 miles from my home in Madison. I ended up not flying anywhere, but that’s another story.

Things have changed. The last time I took New Jersey Transit from my home to the airport was years ago, and it was simple. I took the train from Madison to Newark—Broad Street, then walked downstairs and hopped on the Airlink bus, which stopped at Newark—Penn Station and then Terminal B.

Transportation to the airport is modern now. (more…)