coffee grounds

The quick and the stupid? Or the clever and the slow?

Do students who finish tests quickly score better or worse? This is an interesting question for educators. For good reason there is an implicit bias towards the idea that if it's done quicker, for the same grade/mark, it's better. Yet there is a time and a place for being quick, and a time and a place for being more considered about your answers.

I had an opportunity to do some "research" on this recently. A colleague and I gave an end-of-semester test to 91 100-level (freshman) students in our American history survey. Students had up to 50 minutes to answer 70 questions, with a range of formats including short answer, multiple choice, and identifications. From our mid-semester test we had a fair idea that the median time to completion would be about 40 minutes. Our goal was a test where the challenge was the content, not rushing to finish.

Because both my colleague and I were heading out-of-town shortly after the test, the students answered the test on a single side of paper each. We collected the paper in a box at the end, and then ran all 91 tests through the scanner. This numbered the pages automatically, and all I had to do after we'd marked the tests was rank the scores on the test in Stata (when you have a hammer, everything looks like a nail).

My prior belief before seeing the data was that there might be a U-shaped relationship between the ranks of completion and handing in. Students who did well would either be quick or slow, tortoises or hares winning the race in different ways. Of course, one could also have the prior belief that an inverse U-shaped relationship would hold for the students who did poorly. Some would complete quickly, either realising they didn't know anything or just rushing through the test to go [insert prejudice about under-motivated students here], while others would do poorly through failing to complete all the questions.

By way of explanation in interpreting the graph, a lower rank on completion means the student waited longer to hand in their test. The vertical line on the left side of the graph is the 12 students who all handed in their tests at the very end when we called "time". A lower rank on the test score is a worse score.

What appears to happen is that there is no discernible relationship between when students handed in their test, and the mark they received. A moving average gives us a slightly different perspective.

Recall that a lower rank of handing in the test means students waited longer, and note that the overall mean for the test was a score of 51.3 out of 75 (68.4%, a B on our grade scale).

A moving average forward and back 5 observations shows how student performance varied with submission. The 12 students who waited right until the end to submit had a slightly higher average than the grand mean for the class, but nothing that approached statistical significance. There isn't strong evidence that the slower students are more careful and thus scoring higher.

The average rises towards the middle of the order of tests being submitted, and then falls back towards the overall mean. But note what this last fact shows, the students who finish the test earliest are not doing any worse than average. At least in this class on this test, the students who finished early were not rushing to slack off.

In conclusion, there is some relationship between time to complete the test and scores, but it is not an obvious one.

Nixon is making sense

On NPR yesterday there was a discussion about Iran. To give balance to the programme, the guests were from the right wing American Enterprise Institute, and the right wing Nixon Institute.

What was most interesting was just that, the Nixon Institute. Has Nixon's reputation really been rehabilitated to the point where it's an acceptable name for a public policy institute? Apparently so.

What was then surprising was that the Nixon Institute guest actually did provide balance and lucidity on the issue, saying that America shouldn't try to intervene in the Iranian electoral dispute.

Bad place for a spelling mistake

On United Airlines' reservations page. Wouldn't it be a good idea to have correct spelling in a paragraph asking people to have their correct names on their tickets?

Just a brothel

Ain't New Zealand politics grand?! Just a brothel, running to worry about. I imagine this kind of incident would have caused more consternation in many U.S. states.

Things I don't understand

Seen on the streets of Auckland this past Friday. I guess Catholics are responsible for a lot.

Easter absurdities

New Zealand's laws about opening stores on Easter are more than a little silly. As the New Zealand Herald summarizes it:

Currently the law bans all but a few retailers such as service stations, cafes and dairies from trading on Easter Sunday.

Some tourist destinations in Queenstown and Taupo are also exempt.

Last year dozens of shops ignored the ban, many choosing to pay a $1000 fine in order to keep the doors open.

While New Zealand has no state religion, here we have a law that restricts trading on a religious holiday. I think it might be a legitimate state interest to restrict stores opening on days of genuine national significance like Waitangi Day and ANZAC Day, but Easter? Why should we compel people to recognize a religious holiday?

But the absurdity as always is in the exceptions. It's OK for supermarkets in tourist areas like Queenstown and Taupo to open, but not for supermarkets in "residential" areas to open. Quite what the animating principle behind this distinction is, I don't know. Public and religious holidays are important, but not when there's money to be made off tourists. Every principle has its price. Back in the olden days (1943 - 1977) when hardly any stores were open in New Zealand on the weekends similar absurdities sprung up. New Brighton near Christchurch and Paraparaumu near Wellington were defined—for the purposes of regulating store opening hours—to be outside Christchurch and Wellington because they were beach destinations. So, it was OK for shop assistants in those towns to work on the weekends but not elsewhere.

The Herald also reports that one proposed resolution to this situation is to take New Zealand back to another historical absurdity: the local referendum on store opening hours: "The most recent bill, drafted by Rotorua MP Todd McClay to be introduced to parliament's ballot, calls for a law change allowing local communities to decide whether shops would open."

This was the early twentieth century way of dealing with the problem in New Zealand. Every town, from the cities like Auckland and Wellington to the smallest town with just a few stores, had a referendum on whether stores would open on Wednesday afternoon or Saturday afternoon. The day stores were closed was known as the "half-holiday." The referendum had the appeal of being democratic, of letting the citizens and consumers determine when stores would open, but it had the classic problem of democracy: minority groups were compelled to accept the wishes of majorities. The store that wished to open on Wednesdays was instead made to open on Saturday, when the community might have benefited from having some open one day, and others open the other day.

The cost and internal contradictions of such a system were obvious by the 1930s, and the Labour government's response was instead to regulate in 1944 that virtually no stores be open on the weekend. When the National government liberalised the law somewhat in the 1950s it introduced a byzantine list of what was acceptable to sell on the weekend, necessities being OK and luxuries having to wait until 9am on Monday. A cottage industry in lockable covers to put over the "luxuries" (like magazines) during the weekend developed. The moral principle of restricting store hours had been whittled away. Why it was OK to sell milk but not magazines was not clear.

A similar absurdity is present with the Easter trading laws. Why it's OK to have smaller grocery stores open in every city, and the larger ones in some places but not in others, is not at all clear. The only clear principle is that everything closes by diktat or store owners get to make up their own minds. I suspect that many would choose to close, in the same way that few non-grocery/liquor/pharmacy stores in New Zealand take up their freedom to be open at 9.30pm at night.

Department of funny error messages

From Microsoft Word, opening a document with lots of students' names in it.

Separated at birth?

On the left, Joseph Cassano, blamed for the credit default swaps implosion at AIG that may have caused the global recession. A man just starting his journey through the justice system?

On the right, David Bain who may or may not have murdered his family in Dunedin in 1994. A man just ending his journey through the justice system?

Are they by any chance related?

Are the people who make courseware trying to create RSI?

Start rant ...

The net effect of "courseware" like Blackboard on teaching productivity is positive. You can distribute notes, links, assignments and announcements to students with minimal effort, and it scales well. Communicating with a class of 15 and a class of 170 is pretty much the same.

But there are some frustrations at the margins.

My biggest frustration with Blackboard is that it does a reasonable job of presenting instructors with the tools they need, but it makes those tools too visible to students. What students need to see is digestible chunks of content and information. That content might be a link to a journal article from the university library, a link to an external website, a discussion board for that week's class, and notes from an associated lecture. In Blackboard the default is to put all these things in slightly different places. The default menu categories are organized by how things were made. It would be like if we distributed hard copy content to students distinguishing between whether they were handwritten, typed on a typewriter, or printed from a computer. It is possible to organize things differently, but it takes a lot more work than it should.

Blackboard is also poor at doing the same thing to multiple items. Today I had to make 15 items from last year's version of a course unavailable to students. In some parts of the internet you would select the items in a list, and then choose the action. In Blackboard you have to go into each item individually, choose your new action (making the item unavailable) and then confirm that's what you really wanted to do, and repeat. What could take x mouse clicks takes 4x mouse clicks, plus all the page loads.

None of this has changed as Blackboard has iterated from Version 6 to Version 8. I always take this to be a small sign of trouble in a software market, when a product gets a new integer version number, but doesn't really get many new features, or change its design substantially.

... end rant

My mother always told me not to trust economists

Amongst the many messages I had to read when I returned from holiday was a message with the subject

Dr.George PhD in Economics

This piqued my attention. I like economists, sometimes wondered if I would apply for graduate school in economics before deciding on history. But this was obviously Nigerian spam, where the sender has to establish some credibility before they scam you for money. It was funny to see a PhD in Economics being used as the basis for why you should trust someone enough to send vital details.

My name is Dr.George , Member of Independent Committee of Eminent
Persons (ICEP), Switzerland, and London Office Chapter. ICEP is charged with the
responsibility of finding bank accounts in Switzerland belonging to non-Swiss
indigenes, which have remained dormant since World War II.

Getting up early to watch the One Black

Situated all the way out here on the edge of the world there is a long tradition in New Zealand of getting up early to watch 15 men in black shirts chase a leather ball. So it didn't seem terribly different to get up early to watch one black man chase a leather bible across the Capitol steps.

It was a bit unclear for a while whether we'd actually see coverage of Obama's inaugration. For a few days we thought the only channel showing the event was the local feed of Al Jazeera (they also European sports events and German news shows), which we didn't receive, currently living in a neighborhood located inconveniently out of sight of the transmission tower. But then we got word that TV One, one of the main networks, would be starting their Breakfast show early to bring us coverage. This was a mixed blessing. While we receive TV One, the host of Breakfast is more than a little annoying.

The host is a former radio host who then stood for Parliament for the (conservative) National party, and lost to a transgender Labour party candidate in a fairly conservative rural district (I guess this shows that what passes as fairly conservative in New Zealand is a little different than in America, but that's by the by). By the standards of American network television, the host of Breakfast is unusually voluble about his political opinions. He hasn't been hiding his exasperation with the enthusiasm for Obama.

To a degree this exasperation reflects a real difference in political enthusiasm between New Zealand and the United States. People don't get excited or enraged by local politicians to quite the same extent. It would be like Americans getting really enthusiastic about their state house majority leader. Rarely happens. But the news in New Zealand would have done viewers here more of a service by at least trying to explain the enthusiasm, and respecting it, rather than dismissing it. The charm of the American transition between presidents is that the pageantry is over pretty quickly, but the pageantry and enthusiasm is done well.

In any event, the coverage was unexpectedly good. The best comedic moment came when they decided to skip coverage of the invocation, which was dismissed as "Someone is saying a prayer now" and that they would return to coverage of the event when something important happened. Of all the ways to not have to hear Rick Warren's awful accent this was a good one.

The other moment of comedy gold came when the Breakfast host introduced a former New Zealand ambassador to the United States who had been in the United States for 3 previous inaugurations. But as he often does the host struggled to get quite the right word and said the ambassador had "overseen" three previous inaugurations. The implication being that the Americans couldn't quite get it right without New Zealand oversight. Maybe, maybe. Now if only they could get them to schedule future inaugurations for more convenient New Zealand viewing ...

History on the south side

Last semester I taught a social history course that centred round students doing primary research with the 1924 Houghteling survey of 477 Chicago families. One of the students did a very interesting essay that mapped the distance to work of two groups of employees. Using the file of addresses that he had compiled I then set out to see some of the houses, and whether they still remained. Most of these houses are on the south side of Chicago, where there has been a bit of urban change in the last 80 years.

Setting out with a map and camera I had a list of 40 houses. I did this historical research on foot. To this degree I was being faithful to the original investigators who certainly walked around the Chicago neighborhoods collecting the surveys. With 40 houses to cover I ran. If you are familiar with the south side of Chicago you will appreciate that a white guy running around with a piece of paper and a camera taking photos of people's houses might attract attention. However, I only had one person ask me what I was doing. He was bemused by the explanation that I was an historian. I guess that's what the Chicago Police Department now call undercover agents -- historians. Covering 21 miles (2:50 running, 4:00 total out there) I only got to 31 houses. About half of them were probably the original 1924 house. The results are summarized in the table below for those who are interested.

The diversity of the transformation was interesting. Some of the houses had been replaced by UIC. Others had been replaced by gentrification, particularly in the Bucktown area. Yet others, particularly near UIC and around 18th - 21th St were now largely Hispanic neighborhoods, perhaps today's unskilled immigrant laborers*

This was a particularly fulfilling intersection of running, research and teaching. With the addresses of all 477 families computerized I could envisage a student project to map the transformation of all of these houses. This would even be possible from New Zealand with Google's Street View. But such a project would hearken back to an earlier era of social science which studied neighborhoods as things in themselves. Modern social scientist might perhaps declaim that study of the neighborhood as superseded by a methodological focus on the individual and family in different contexts. So, there goes the neighborhood.

You can see a picture of the transformation here: www.evanroberts.net/chicago_houses

* I hasten to add that I am not implying Hispanics to be unskilled laborers, but am echoing the title of the original research.

Continue reading "History on the south side"

Spoons: Watch it a couple of times

Like summertime TV everywhere the options on New Zealand TV in the summer are pretty bad. That probably explains how they acquired Spoons to broadcast at odd times like 10:20 on a Tuesday. Spoons is good foam roller and stretching time TV. Not so funny that you fall off the foam roller, yet not so dull that I stop roller-ing and stretching. This, of course, is why there was no second series of Spoons.

There is one overarching premise to the sketches on Spoons: people don't always tell their romantic partners everything they are thinking. The secondary premise of the sketches often seems to be misanthropy. Again, this is why there was not a second series. The great insight of the Hollywood romantic comedy in all its similarly repetitive glory is that a budding romance is a nice thing, but with many opportunities for humor. Spoons is bleak in its assessment of human nature. I enjoy black humor, but there's only so much of it I can take. It turns out 30 minutes in one sitting is a little much.

The best part of Spoons is the sketch that seems to end every show, where a man goes to his storage unit containing just a folding chair, calls his wife and says he'll be home late for some plausible reason (traffic, supermarket delays, urgent deadlines etc). The repetitive sketch works because it's explicit—the same character, the same empty storage unit, the same structure of the conversation with his wife—and also because of the element of the absurd. Are there really people who hire storage units to get away from their families? (any correspondence on this matter will be kept anonymous ...)

The rest of Spoons is too repetitive in the structure of the sketches, varying just the actors and the settings. It's funny to see one skit based on the idea that men won't come out with their partner's female friends because of what women [apparently] talk about without men present. It's not nearly as funny the 3rd time with more variation in the clothes the actors are wearing than the actual joke.

Yet the reason I've persisted with watching Spoons instead of the other 5 options is the refreshingly abrasive British humor. The abrasive humor is another way of saying misanthropy, but it is a humor you don't often see on American TV. It's a pity the writers and actors couldn't diversify the sketches in Spoons a little more, because the method would apply to other situations than dating. The promise of the series seems to have been lost in the over-application of a good idea.

Marriage is not recession proof, let alone weddings

As the financial condition of the country worsens, the wedding industry, so long considered recession-proof, is seeing fairy-tale weddings stripped of their sprites, their sparkle and everything else that suggests splurge. (from the New York Times, "Recession? Time to Slash the Flower Budget"

This puzzled me. Last time we had a long and severe depression marriages plummeted, as you can see from the figure below. Perhaps the current recession will be different. We are starting from income levels significantly above those of 1929. The magnitude of people's reactions to the current recession will be different than in 1929, though the direction may be similar. There is now, as the same NYT article, suggests greater policy support for marriage with tax and health insurance arrangements prodding people into formalizing relationships that might otherwise just be people living together.


Source: Historical Statistics of the United States, Tables AE507-508.

Defining gaffes downward

It was, of course , the addition of Joe Biden that dealt an initial body-blow to Obamaland's disciplined corporate culture. Biden committed his first gaffe even before the end of his coming-out speech, referring to his new boss as "Barack America." In his early days on the trail, he publicly suggested Clinton would have made a better running-mate and mistakenly name-checked a future "Biden administration."

From Noam Schieber's New Republic piece on Obama's personnel management

This is ridiculous. Saying "Barack America" and referring to a future Biden administration are true examples of mis-speaking. String enough words together in the day, and chances are that parsed literally some of them will not make total sense. That chance rises when you're working long hours on an election campaign, dealing with people you don't know in many different places and talking about lots of different topics.

Perhaps, perhaps, you can say that Biden's statement Clinton would make a better running mate is a true gaffe, but even then it's so dependent on context. There are times when the right political answer is to be humble and promote someone else.

Unattended bags

Denver airport, 7 November 2008.

What is it they say about making sure you have possession of your bags at all times at airports?

Where in the world is Osama Bin Laden?

Seriously, no message from Osama on the eve of the election? Is he waiting for election day? Is he dead?

Debate reactions

Here I am at Denver Airport (where, by the way, the free wireless has improved substantially) and watching McCain and Obama debate. The dial is interesting, it seems the undecided voters like what both candidates say for the most part; tho' I think McCain has gotten more extreme negatives and Obama more extreme positives from the dial.

But the crowd here at gate B55 for the flight to Minneapolis are silent. There are 50 people and no-one has clapped, no-one has hmmphed, no-one has laughed. I guess this demonstrates the more-American idea that you shouldn't talk about religion or politics with strangers. I would be interested to watch the debate in a bar (next election! come on 2012!) because that is my only point of comparison for watching political debates in public places. I watched a New Zealand election debate in a bar in 1999, and it was like being at a sporting event. People cheered, they jeered, they laughed.

Now, it's likely if you self-selected to be in a bar to watch a political debate you had a greater interest in politics than people who somewhat randomly ended up at the same gate for a plane together, but still. An airport seems like a slice of middle America, and I am not picking up any sense of how the average American is feeling about the election. Guess I'll have to rely on the internet, which you can do from overseas in your pyjamas. So, the audience is unusually quiet here. Partly that might be to actually hear the debate because unlike normal airport tv the sound is down at a frustrating just a little too quiet level, rather than the normal just a little too loud.

And in other news it snows there too

Turning to the Star Tribune to procrastinate get the latest on Norm Coleman's suitability for public office (see here) I learned that Minnesota has deer and cars ...

I suppose he could

After running 2:03:59 I'm glad Gebrselassie feels confident he can run a minute a mile slower.