Thursday, July 2, 2015

For the math nerds in audience (or as we call them here, "the audience")

Let's get real. If you're reading a blog originally called "Observational Epidemiology," the cool kids' boat has sailed.

I've got a post up on the teaching blog on the case against axiomatic rigor in lower level classes, but the best part is probably this anecdote.
A few years ago, when I was teaching math at a big state university, a colleague told me the following.

She was comparing notes with a professor at a nearby school on how their respective real analysis courses were going. She told him that they had just proved that the square root of two was an irrational number. He laughed and said she was way ahead of him; his class had just proved that the square root of two is a number.

Wednesday, July 1, 2015

John Lott's tertiary defense

I've already wasted way too much time following this exchange between Andrew Gelman and John Lott and reading up on the Lott saga. In retrospect, the man isn't that interesting and I doubt you can find an issue I care less about than gun rights/gun control. Nonetheless, I did notice something about Lott's defense and, having wasted the time following all of those links, I might as well get a post out of it.

Lott was responding to a comparison Gelman drew between him and Michael LaCour. I'm not going to go into the details here (that's what the link at the top of the page is for). What caught my attention was what popped when I checked out the sites Lott provided as support.

The first thing you notice is the tone [from supporter James M. Purtilo]:
However our close observation of Wikipedia points to the company’s willing participation in efforts to promote biased material into “fact.” The company’s business relationships give it high page rank in many search engines, so searches on many terms, disputed or not, naturally draw consumers to Wikipedia material. (Google in particular, a growing icon in politically left-leaning circles, gives high priority to Wikipedia entries.) When controversial topics are ‘frozen’ by Wikipedia editors, they are apparently done so in a form most beneficial to the left wing view, without disclaimer warning a well-intentioned researcher that he or she may be incorporating disputed or unsupported material. When journalists accept such material, whether innocently or by knowingly giving faint diligence to an obligation to get ‘outside’ authoritative sources, the quality of material presented on Wikipedia becomes inappropriately boosted in the eyes of the public. The net effect is a ‘bootstrapping’ process, in which the quality of material which tends to serve liberal political needs is artificially inflated and distributed.
But the main thing that struck me was that the links Lott gave all seemed to attack tertiary sources like Wikipedia and a brief item the Washington Post. The WP focus is particularly odd since pretty much all that writer does is describe a Timothy Noah column from Slate. Lott provides hundreds of words on the Post but I can't find anything on Noah. I also couldn't find any references in the piece to Lott's best-known critic, Steven Levitt, which is strange since Levitt definitely left him an opening.

I'm not sure what the strategy here is. Lott's idea may be to keep the charges from spreading, or perhaps he's just not a very effective debater.





By the way, in the social sciences, Lott vs. Levitt is basically...



I really don't know who to root for.

Tuesday, June 30, 2015

Mark Thoma continues to shine

Nobody talks about the assumptions behind free markets better than Mark Thoma, who has a new piece on the subject.  It really should be required reading, because it sets the pattern of regulations that all society's develop in context and makes it hard to have an absolutist view on a lot of subjects.

At the same time, it appropriately acknowledges just how powerful this process can be when the necessary preconditions exist.

Cracked, on the other hand, is very good at talking about math

I tend to avoid Cracked.com. Their articles are thoughtful, informative and enormously entertaining. They can discuss complex, even technical subjects in a clear and engaging way. All of this makes the site a dangerous time sink and I just can't afford to hang ouot there.

From 6 Small Math Errors That Caused Huge Disasters
#4. A Huge Walkway Collapses Due to a (Seemingly) Inconsequential Design Change

When designing their newest hotel to be built in downtown Kansas City, the fine people at Hyatt Regency wanted all the bells and whistles in it. The architectural firm in charge of the building design came up with a series of aerial walkways suspended from the ceiling so that guests could people-watch from a heightened vantage point. All in all, it was a pretty nifty feature. Until it suddenly collapsed and killed more than a hundred people.

The Laughably Simple Flaw:

One long rod was replaced with two short ones.

If there's one principle consistent across all human nature, it's that we will always prefer the path of least resistance (i.e., "if you can get away with a half-assed job, do it"). The original plan was for two walkways that were directly on top of one another to both be supported by one very long rod that would anchor into the ceiling. Like so:



Easier to work with, easier to install, works exactly the same. Right?

That little change killed 114 people, injured 216 more and cost $140 million in lawsuits.




Look at the first image again.




One rod, two nuts. Each nut only has to carry the weight of its own platform. Which is good, because each nut (and the welded beam it's screwed to) is only rated to carry the weight of one platform.

Now look at the second image. See the nut we've labeled "OH SHIT"?




That one single nut now has to carry the weight of BOTH platforms, and all the doomed tourists standing on them. Look obvious? Congratulations, because none of the professionals at either company caught it.

And so, one night during a dance competition, the stressed "OH SHIT" nut cleaved clean through the beam and the walkways collapsed.

During the ensuing lawsuits, it came out that neither the steel company nor the engineering firm in charge of construction had even bothered to do a back-of-the-envelope calculation that would have shown them this glaring flaw.

Monday, June 29, 2015

There may be a quality control problem here -- nearing the end of the EngageNY thread

At the teaching blog, a follow-up to the language of Eureka post using the same lesson:

Eureka Math Tips for Parents -- worst SAT prep question ever

Here's the offending passage this time.


[And before you ask, the answer is no, a rectangle and a triangle can't have corresponding parts.]

I have lots more material -- hell, that same page had a different problem that screwed up by omitting the AAA similarity theorem -- but I think that we've already uncovered an unacceptable number of major errors after only a few spot checks. More examples would just be piling on.





Sunday, June 28, 2015

On the teaching blog

More on appropriate and inappropriate use of formal language in math lessons,

Eureka Math Tips for Parents -- well, that clears up everything

Friday, June 26, 2015

Third, when you call yourselves "Great Minds," you're just asking for trouble

A bit more background on the Eureka Math thread (see here, here and here).

First off, I volunteer as the math adviser for a urban after school program here in LA and based on that not-at-all random sample, Eureka Math is widely used in the LAUSD and both kids and tutors (including those with math backgrounds) hate it.

Second, as this Quartz article by Rachel Monahan shows, Eureka Math is very much the accepted choice for schools looking to align their instruction with the Common Core Standards.
Louisiana published a review of Common Core curricula last year, and gave EngageNY’s Eureka Math a top ranking, leading a large number of districts in the state to adopt it, according to officials with the nonprofit Great Minds Inc., which developed Eureka Math for EngageNY. Parts of Core Knowledge also ranked at the top along with one textbook series.

Favorable reviews there and elsewhere of the free EngageNY materials have helped expand interest. Achieve, a nonprofit group that backs the Common Core standards, gave three Expeditionary Learning units its highest ranking.

“Do we want as many districts as possible adopting our stuff? Sure. Am I more interested in our setting a new standard for the quality of instructional materials in reading and math? Yes,” said Great Minds executive director Lynne Munson. “I’m vastly more interested in seeing that more students are learning these subjects well than in selling anything to anyone.”

Thursday, June 25, 2015

What high school students are learning about statistics

Yet another post up at the teaching blog on the Common Core affiliated lessons from EngageNY. Most of it focuses on the language we use to teach math, but I would like our regular readers to check this out (you can find the original lesson here).
Suppose newspaper reporters brainstormed some headlines for an article on this experiment.  These are their suggested headlines:

A. “New Treatment Helps Pericarditis Patients”
B. “Colchicine Tends to Improve Treatment for Pericarditis”
C. “Pericarditis Patients May Get Help”

7. Which of the headlines above would be best to use for the article?  Explain why.

Headline A would be the best because this is a well-designed experiment.  Therefore, a cause and effect relationship has been established.  Headlines B and C talk about a tendency relationship, not a cause and effect relationship.
I've read this over multiple times and have run it past an old professor of mine who teaches experimental design and we keep coming to the same conclusion. In a lesson on drawing inferences from experimental data, the authors seem to believe that 'causal' means 'deterministic."

That would be bad.

I have more concerns in my original post, and those represent only a fraction of the problems I found in the section. I recommend you take a look for yourself, and when you do, remind yourself that this is widely considered the gold standard of the new wave of instructional materials.

Wednesday, June 24, 2015

Defining dysfunction

This paragraph from a recent Paul Krugman post reminded me of something I've been meaning to dig into for a while.
A brief aside: I don’t think it’s right to call this a case of Washington “dysfunction”. Dysfunction is when we get outcomes nobody wants, or fail to do things everyone wants done, because there doesn’t seem to be any way to package the politics. In this case, however, people who oppose TPP voted down key enabling measures — that is, they got what they wanted. Calling this “dysfunction” presumes that this deal is a good idea — and that kind of presumption is precisely what got successfully challenged yesterday.
We hear “dysfunction” thrown around a lot (often by me), so it might be a good idea to pin down some definitions. Krugman is definitely on the right track, but statements about “nobody” and “everybody” are obviously unrealistic. Every scenario makes somebody happy, up to and including the rise of Cthulhu and his dark, chthonic host. A workable definition will have to take that into account, as well as considering differing intensities of opinion.

A system is dysfunctional if there is no consistent weighting of preferences that corresponds to its actions. (I'm going to be careful not to let this drift into a discussion of voting paradoxes because a good portion of this audience knows a great deal about the subject and I would have to do serious research to make sure I didn't make a fool of myself.)

For example, a group could do what the plurality wants, or it could use some sort of weight by rank (first choice is worth five points, second is worth four...), or it could take into account strongly held positive or negative opinions.

Let's use restaurants. A group might go to an Armenian place because three out of seven listed it as their first choice, or they could go to Chipotle because six people listed that as their second choice, or they could take Chipotle off the list because one person refused to go (I'm with that guy. Living in LA and going to Chipotle is like living in Rome and going to Pizza Hut). All of these decisions are consistent with a functional organization.

If, on the other hand, the group ends up going for Thai when everyone would have preferred burgers, that's dysfunctional. I can’t think of a reasonable and consistent weighting scheme that can produce that result.

A political party is more complex than a group of friends, but in some ways it may not be that much more complex. I’ll try to flesh this out later, but for now, while you have to be careful talking about what a large group “wants,” I suspect that there are a lot choices that the GOP would “like” to make (infrastructure spending, for instance) in the same sense that those friends would “like” to be having burgers now.

Based on these definitions, for large chunks of the Twentieth Century, I'd say that the Democratic Party was the more dysfunctional. The Republicans, however, do seem to be making up for lost time.

Reading over this, it's pretty clear that I have a ways to go before I have a proposal for something coherent and measurable and usable, but I do believe there is something out there, What's more, I suspect that, in 2015, it's probably more important to worry about dysfunction than about ideological extremism.

Tuesday, June 23, 2015

A genuinely funny conspiracy theory

Maybe I'm just getting around to noticing, but it seems that Cracked has been pushing their videos more into the sketch category. The results have been a bit mixed, but some of the clips have been very good and the site has built up a great of good will over the years.

I may be biased -- I have a fondness for satiric conspiracy theories and a bad feeling about the practice of making big budget films out of TV shows (particularly the recently departed) -- but, with that caveat, I think you'll enjoy this one.


Monday, June 22, 2015

Captain Outrageous

My big complaint with business journalism in the Ithuvanian Age is not just that journalists mistake luck and hype for genius, but that they miss genius when they see it. Reed Hastings can get on the cover of anything; Neal Sabin, who essentially invented a large and highly profitable media industry, doesn't even get a Wikipedia page.

There is an aesthetic to business just as there is to sports. The great players do look good on paper, but there is a pleasure in watching their style and their brilliance that the stats simply can't capture.

And nobody ever had more style than Ted Turner.



Friday, June 19, 2015

Uber and rules

From the comments at Cathy O'Neil's page:
Uber is a worldwide company; NYC type medallions are found in just six US cities. There’s absolutely no evidence that inflated medallion values in these six cities had anything to do with medallion owners pocketing obscene taxi profits at the expense of riders and drivers (there are no obscene taxi profits in any city; medallions are a financial instrument, and inflated in line with comparable instruments). The “heroic innovators versus corrupt protectors of the status quo” framing is designed to prevent anyone from actually examining whether Uber can produce taxi service much more efficiently than a reasonably run Yellow Cab, or where these massive efficiency gains might come from, or whether they are sustainable over time, or why no one else had ever thought of them.
This was generated by a question that Cathy posed:

On the one hand, it does seem to be a different act to raise your hands on Broadway versus using an app on your phone. But by the time we have chips implanted into our heads, just thinking the words “hail a taxi” might do the trick, and that’s where the grey area lives. Or, put it another way, yellow taxis might also want to have hailing apps, and in fact they really should. 
I can attest that yellow cabs have hailing apps in some cities already, Seattle for example.  Should that allow those companies to evade transportation regulation?  This is very much like the sales tax issue with Amazon -- slight differences in business model lead to a discussion as to whether the generally accepted rules apply at all.  In general, I think there are a lot of pernicious regulations and there is a lot of things that can be done to make things more efficient. 

But I also believe in treating groups fairly.  I don't think that technical exceptions to rules should be the goal -- rather we should overturn bad rules.   I'd have more sympathy if the new entrants were selling their app to all comers (pure software company) or if they were pushing for the rules to be revised wholesale into a new regulatory regime that all of the relevant players could participate in.  It isn't always the case that the status quo is good, but exception-based regulation seems to be a dangerous way to proceed as that can create a less competitive market.  Even Ayn Rand thought that was bad (see the first part of Atlas Shrugged and Taggart Transcontinental). 

Thursday, June 18, 2015

The New Yorker's culture desk could use a fact checker

I recently came across an uncredited piece that drove my inner film geek crazy. About halfway into the review of Ace Records’s new compilation, “Come Spy With Us: The Secret Agent Songbook,” I came across this.

[emphasis added]
The world of spy themes doesn’t stop at Bond (or at Bond offshoots or Bond antidotes), and neither does Ace’s set. Lalo Schifrin’s immortal “Mission: Impossible” theme is here, along with the Challengers’ version of Hugo Montenegro’s “Theme from the Man From U.N.C.L.E.” Both of those illustrate the relationship not only between spy music and surf music—similar in instrumentation, similar in insistence—but also between spy music and the music of spaghetti Westerns.

...

There are far too many good selections here to list them all: Billy Strange’s “Our Man Flint,” Nancy Sinatra’s “The Last of the Secret Agent” (Flint and Sinatra would collaborate on the theme song for the Bond film “You Only Live Twice,” which isn’t on the set) [That should be "Strange and Sinatra," Derek Flint being fictional and all. It should also be noted that the version of “You Only Live Twice” that most of us are familiar with is by Barry and Sinatra. Billy Strange had nothing to do with it -- MP], and Matt Monro’s “Wednesday’s Child.”   
Billy Strange was an arranger and session musician now best remembered as a member of the legendary Wrecking Crew. Hugo Montenegro was a minor film and TV composer (other than I Dream of Jeannie, I doubt any of his compositions would register if you heard them) who was best known for cheesy but popular cover arrangements.



Both released albums of covers of soundtracks of popular movies and TV shows. As far as I can tell, neither had anything to do with the original scores. Those came from composers such as Ennio Morricone, John Barry and, in this case, the man who wrote the theme for the Man from UNCLE and composed most of the music for the show's first season and who scored both Flint films, Jerry Goldsmith.

For movie people, Goldsmith is kind of a big deal:
Jerry Goldsmith has often been considered one of film music history's most innovative and influential composers.[8] While presenting Goldsmith with a Career Achievement Award from the Society for the Preservation of Film Music in 1993, fellow composer Henry Mancini (Breakfast at Tiffany's, The Pink Panther) said of Goldsmith, "... he has instilled two things in his colleagues in this town. One thing he does, he keeps us honest. And the second one is he scares the hell out of us."[65]  ...  In a 2001 interview, film composer Marco Beltrami (3:10 to Yuma, The Hurt Locker) stated, "Without Jerry, film music would probably be in a different place than it is now. I think he, more than any other composer bridged the gap between the old Hollywood scoring style and the the [sic] modern film composer."[67]
For someone writing about film music, crediting Montenegro or Strange with a Goldsmith composition is the kind of mistake that makes you wonder how much of the writer's expertise came from the liner notes. Perhaps worse, it is such an easily avoidable error. Thanks to Wikipedia, it takes so little time to get the facts right.

In fairness to the author, some of the critical points are valid (such as the relationship between spy films and surf music. For example, check out the arrangement from this sequence from Our Man Flint,



But even good arguments are difficult to take seriously when they come with careless mistakes.

p.s. I didn't want to go full nerd in the middle of a post, but if you feel like releasing your inner spy geek, I recommend checking out these discussions of the various arrangements of Man from UNCLE themes (including the revelation that Goldsmith hated Lalo Schifrin's new arrangement).

p.p.s. I ran this past an actual authority, Brian Phillips. He pointed out another one I should have caught: "Though Bill Cosby starred in “I Spy” as early as 1965 (the brassy Roland Shaw theme is included)..."  The I Spy theme was, of course, by Earl Hagen who was, in Sixties television, also kind of a big deal [Andy Griffith Show, Dick Van Dyke Show, etc.].

Brian also questions whether the bassline to "Come Spy With Me"  is really James Jamerson.

Wednesday, June 17, 2015

I don't have time to comment on this one

But I really want to.

The David Brooks files: How many uncorrected mistakes does it take to be discredited?

Eugen Weber explains the origin of window shopping

I've got a big MOOC thread (actually a MOO? thread) involving Dr. Weber and his seminal video course, the Western Tradition (previously discussed here).

Whenever I research one of these megathreads, I end up learning all sorts of interesting things that don't quite fit in with the thread. For example, I'd never associated the Industrial Age with peering through a shop window.