<body><script type="text/javascript"> function setAttributeOnload(object, attribute, val) { if(window.addEventListener) { window.addEventListener('load', function(){ object[attribute] = val; }, false); } else { window.attachEvent('onload', function(){ object[attribute] = val; }); } } </script> <div id="navbar-iframe-container"></div> <script type="text/javascript" src="https://apis.google.com/js/plusone.js"></script> <script type="text/javascript"> gapi.load("gapi.iframes:gapi.iframes.style.bubble", function() { if (gapi.iframes && gapi.iframes.getContext) { gapi.iframes.getContext().openChild({ url: 'https://www.blogger.com/navbar.g?targetBlogID\x3d12969692\x26blogName\x3dLearning+Strategies\x26publishMode\x3dPUBLISH_MODE_BLOGSPOT\x26navbarType\x3dBLUE\x26layoutType\x3dCLASSIC\x26searchRoot\x3dhttps://larrydavidson.blogspot.com/search\x26blogLocale\x3den_US\x26v\x3d2\x26homepageUrl\x3dhttp://larrydavidson.blogspot.com/\x26vt\x3d-7810603580866381255', where: document.getElementById("navbar-iframe-container"), id: "navbar-iframe" }); } }); </script>

Sunday, December 31, 2006

New Year's Eve at the Ashmont Grill and High Fidelity

To celebrate the New Year, Barbara and I just had dinner at the Ashmont Grill, which offered a special menu for New Year’s Eve. Although we hadn’t really intended this to be a “going out in public” experience — like attending First Night, say — it turned out that we knew the people at all three of the tables next to us! Anyway, the food and the experience were highly commendable, as usual. You probably won’t find these on the regular menu, but I highly recommend both the duck confit appetizer and the lamb chops entree, which were what I had last night. Whatever their menu of the day might be, I highly recommend that you take a trip into Dorchester — perhaps not your usual location for dining out — and eat at the Ashmont Grill, even if it’s for nothing fancier than cheeseburgers and onion rings (both of which happen to be first-rate there, by the way).

After the excellent dinner we went home to watch videos. We started with High Fidelity, but Barbara had already seen it and I found it terribly boring, so we gave up on it. Oh, well.

Labels: , , ,

Friday, December 29, 2006

Somebody Else's Music

I just finished reading Somebody Else’s Music, by Jane Haddam. One of the best in her Gregor Demarkian series, it is distinctly darker than its predecessors. Most interesting to a high-school teacher is its theme of high school as real life. There’s plenty of popular fiction — both books and movies — exploring the sociology of life in high school, but this novel is about people in their mid-50s. Although they’ve been out of high school for nearly 40 years, their lives and relationships are still largely dominated by events that happened when they were teens. This theme is so relentless that at first I found it implausible, but then I thought about the setting and became convinced. The book takes place in a small town in north-central Pennsylvania, a town where a majority of residents stay for their entire lives. Most of the graduates of the local high school either go to a nearby community college or don’t go to college at all. Football players and cheerleaders are the preeminent social group, and the lines between who’s in and who’s out last for a lifetime. It’s very different from where I teach, in Weston, and where I live, in Boston, but that doesn’t make it unbelievable. In fact, it’s probably much more typically American than either Weston or Boston is.

Anyway, this story was clearly inspired by both Lord of the Flies and “The Lottery.” Haddam even makes the occasional explicit reference to one or the other, as well as implicit references such as memories of chanting “slit his throat.” It’s all a pretty grim picture of how teenagers (and people in general?) treat those who are different. I’m not so naive as to think that this portrayal is inaccurate — we have plenty of real-world examples that only reinforce it — but it certainly doesn’t impinge much on my everyday life. And yet... and yet... even at Weston High School one of the major social problems is bullying, according to recent surveys. But surely it is not condoned by the faculty, as it is in the present-day fictional high school of Somebody Else’s Music, where one of the alumnae of 1969 is now principal. (She explicitly blames a victim rather than the bulliers in an incident that I hope is not representative of any real high-school administration.) But then I think back to my own high-school experience, where it was absolutely clear that the faculty turned a blind eye to bullying. And what are present-day consequences of that acquiescence? Who can I remember among the students that I went to high school with in the sixties? The first one who comes to mind is George W. Bush...

Labels: , ,

Thursday, December 28, 2006

An obligation to vote?

Everyone knows about the 2004 decision of the Massachusetts supreme court legalizing gay marriage, and everyone knows that laws banning gay marriage have been passed in many states and are in the pipeline in others, but out-of-staters may not be aware of the current state of such efforts in Massachusetts. It all hinges on a question of mathematical logic.

First of all, a bit of background. An initiative petition sponsored by opponents of gay marriage was signed by enough voters to have it sent to the state legislature, commonly known as The Great and General Court of the Commonwealth of Massachusetts. The legal process in Massachusetts is that the measure will be placed on the ballot if approved by at least 25% of the legislators meeting jointly as a constitutional convention. The legislature has twice refused to vote on the measure, presumably because it is opposed by more than 50% of the members but fewer than 75%. So our esteemed governor, Mitt Romney, as part of his efforts to shore up his new-found conservative credentials, brought a case before the Supreme Judicial Court (SJC) to try to force the Great and General Court to vote. (Bear with me now about the names: the Supreme Judicial Court is truly a court; the Great and General Court is the legislature, not a court.) The SJC rightly refused to do so, unanimously declaring that it would be a violation of the separation of powers, but I am mystified by their claim that the legislature does have an obligation to vote. As I say, it all hinges on a question of mathematical logic. IANAL, of course, but the issue seems clear to me. In an article in the Boston Globe, Romney quotes a sentence from the state constitution:
Romney — weighing a run for GOP nomination for president — even sent a copy of the state constitution to all 109 lawmakers who voted to recess the special legislative session.

“The constitution quite plainly states that when a qualified petition is placed before them, the Legislature ‘shall vote.’ It does not say ‘may vote,’ or vote if procedures permit a vote, or vote if there are enough of the members in the chamber. It says, ‘shall vote.’” Romney said.

Not exactly, according to several legal experts, who say that reading of the constitution is flawed. They say that, for better or worse, lawmakers have acted within the bounds of the constitution, which stops short of ordering they vote up and down on the measure.

“That’s a nicely symbolic way of making his point, but it’s a little empty at the end of the day,” said David Yas, publisher of Massachusetts Lawyers Weekly. “The ballot initiative process is part our Democratic process, but so are the legislative tricks and treats.”

The tussle hinges on the interpretation of a single sentence in the constitution: “Final legislative action in the joint session upon any amendment shall be taken only by call of the yeas and nays.”

Supporters of the constitutional amendment, like Romney, say the sentence is a clear mandate that lawmakers must vote directly on the measure itself.
But that’s clearly wrong! You can’t just skip over the word “only”! The Globe article goes on to quote Lawrence Friedman, a constitutional law professor at the New England School of Law, who observed that the language “dictates the form of a vote, but does not mandate a vote.” Here’s an example that shows why the word “only” is so crucial:

Suppose I put the following notice at the top of a two-part test:
Calculators shall be used only on Part A.
(Yes, it’s a bit stuffy — lawyers’ language, not teachers’ language — but we’re really talking about laws here, not math tests.) If I had omitted the word “only,” it would be an injunction to use calculators on Part A, apparently requiring their use (as in Romney’s reading of the state constitution). It would be silent about Part B, which might or might not allow calculators. But the word “only” changes everything, reversing the logic to create the converse of the meaning; now it allows calculators on Part A and implicitly prohibits them on Part B. Similarly, the state constitution says “only by call of the yeas and nays,” meaning that they’re not allowed to vote by any other process, not that they must vote.

Labels: , ,

Wednesday, December 27, 2006

Elmira 2006

This year’s trip to Elmira was not nearly as interesting as last year’s.

Labels: ,

Tuesday, December 26, 2006


On NPR’s All Things Considered tonight, there was actually a report about a math problem! To quote science correspondent David Kestenbaum’s report on the Poincaré Conjecture:
The journal Science’s “breakthrough of the year” for 2006 is the solution of a century-old math problem. The story behind the solution is quite a soap opera. It includes a Harvard math wizard, a reclusive Russian genius, a one-million-dollar prize, an award-winning journalist, and The New Yorker magazine.
The New Yorker article provides a lot of mathematics and considerably more human interest; it is definitely worth reading. Also, check out the Clay Mathematics Institute’s description of the Poincaré Conjecture, a description that almost succeeds in making it understandable.


Sunday, December 24, 2006

The Lincoln Lawyer

Recently I read The Lincoln Lawyer, by Michael Connelly, on the strength of an enthusiastic review in the Boston Globe last year. I was not disappointed.

Maybe the Globe review explained the title, but if so I didn’t remember. Is the lawyer from Nebraska? Is he somehow connected to Abraham Lincoln? No, it’s just that he drives Lincolns — and yes, that is relevant to the story. Anyway, this novel has a dramatic plot, with several major twists, which may not be as effective as Jeffery Deaver’s but are still exciting. Most important, however, is Connelly’s character development, focusing on the protagonist, who starts out seeming to be nothing but a sleazy, win-at-all-costs defense attorney.

He turns out to be much more complex than that.

You’ll have to read the book to find out how.


Saturday, December 23, 2006

Windows Vista

I’m shocked, shocked, to see Microsoft labeled as “imitator, not innovator” in the review of Windows Vista in the New York Times of all places.


Friday, December 22, 2006

Balance or integration?

In many school districts, including Weston, we try to resolve the Math Wars by promoting a balance between skills and concepts. We tend to adopt the party line as promoted by former Education Secretary Richard Riley:
We are suffering here from an “either-or” mentality. As any good K-12 teacher will tell you, to get a student enthused [sic] about learning, you need a mix of information and styles of providing that information. You need to provide traditional basics, along with more challenging concepts, as well as the ability to problem-solve, and to apply concepts in real world settings.
I used to agree. But my sister, Ellen, has recently convinced me that balance is the wrong goal: what we need is integration of skills and concepts. Here are two recent true stories to illustrate the point:
  1. Mary buys a large rug and decides to have it shipped home, since it’s too big and too heavy for her to carry it in her car and then get it into the house. So she arranges with the store clerk to have it shipped. They roll up the rug and place it on the scale. Oh, no! It’s three pounds about the maximum weight for this shipper.

    So the clerk instructs Mary to fold the rug in half and then roll it up again. “What good will that do?” asks Mary.

    “It will weigh less,” replies the clerk.

    Mary points out that it will indeed be smaller in one of its dimensions, but its weight won’t change. “Yes it will,” insists the clerk; “if it’s smaller, it will weigh less.”

    An ill-advised attempt to explain conservation of mass turns out, of course, to be of no avail.

    While the clerk’s misconception is more about physics than math, it’s surely tied in with the general belief that perimeter is always directly related to area. If you “increase” a rectangle from 6-by-8 (perimeter 28) to 3-by-12 (perimeter 30), you have surely increased its area. Right?

  2. On a recent test, one of my better students, whom we’ll call Matilda, consistently gets slightly incorrect answers in calculating outputs of an exponential function. The instructions said to “round off correctly to the nearest tenth of a pound,” and the calculator gave answers like 3.24312237 and 4.724646398 pounds, but this student got 3.1 and 4.6 pounds respectively. What was Matilda doing wrong? I scratched my head.

    You’ve probably figured it out already, but I asked Matilda to show me her calculator work and explain her answers. She indeed got 3.24312237 and 4.724646398, and then explained that the hundredths digit was less than 5 in each case. The rule, she said, told her that when a digit is less than 5 you need to round down, so she rounded the tenths digit down...
What do these anecdotes have in common? In both cases there was a disconnect between skills and concepts. No amount of “balance” would help, but a successful integration of the two would reinforce the necessary connections and prevent belief in a rule that doesn’t make any sense.

Labels: , ,

Wednesday, December 20, 2006

Black Maps

Black Maps, by Peter Spiegelman, is clearly not for just any random reader of mysteries. It combines the loner private eye — traditional in the noir side of the genre — with the much less hot-blooded (and tiny) sub-genre of financial and other white-collar crime. So if you’re turned off by either of these points of view, you’ll probably give Black Maps a miss.

That would be a pity, because the page-turning plot, the character development, and the vivid sense of place (New York City) all turn out to be much more important than either the noirishness or the financial shenanigans. I can’t say much more without risking inadvertent spoilers. Don’t reject Black Maps because you don’t like noir. Don’t reject it because you don’t like financial mysteries. Just read it.


Monday, December 18, 2006

The Russo-Japanese War (of the condiments)

My colleague Boris gave me a jar of horseradish mayonnaise imported from Russia. Having enjoyed it on roast beef sandwiches, and even ham sandwiches, I decided to do a comparison with the Japanese equivalent, purchased at Kotobukiya in the Porter Exchange (a.k.a. “Little Tokyo”) in Cambridge. Japan won the real Russo-Japanese War, which may explain why their mayo is definitely hotter than the Russian variety — too hot for sandwiches, in fact. It’s fine in small quantities on appropriate varieties of sushi, but it needs to be diluted 50-50 with regular mayo when used on sandwiches. Russian wins for that purpose, since it can be used as is. I just thought you ought to know.


Saturday, December 16, 2006

Scheme overheard

This would be a pretty surprising remark to overhear at the next table at a random Chinese restaurant:
I’m really enjoying programming in Scheme. At first I hated it, since it was so different, but now I really like it.
I really did overhear that remark.

But I guess it doesn’t exactly count as a “random Chinese restaurant,” since it was at Mary Chung’s, and the table appeared to consist of ten MIT students.

Labels: ,

Friday, December 15, 2006


All the word geeks, game show geeks, and trivia geeks out there should go read Brainiac, by all-time Jeopardy champ Ken Jennings. Part autobiography, part history of game shows and trivia contests, this fast-reading book is fun to read and informative to boot. You can get the inside scoop on Jeopardy and find answers to all those questions you wanted to ask but didn’t. Or should I say that you can find questions to all those answers...?


Thursday, December 14, 2006

Misoverestimating minority populations

It worries me that people so consistently overestimate the populations of all minority groups. We know that estimation is difficult, but the magnitude of the errors that I see has genuine political implications for us as citizens. This isn’t just a Weston problem or just a Dorchester problem: a white student from Weston and a black student from Boston are about equally likely to think that 40% of Americans are Jewish. Or that 50% of Americans are black. Or that 30% of Americans are Muslim.

What’s wrong with this picture?

To start with, how do people think that Bush ever got elected if their perception of American demographics were even remotely accurate? And what’s more troubling is that these vastly inflated impressions of the number of Jews or the number of blacks are all too reminiscent of Nazi Germany, where Hitler played on fears that the Jews were too numerous and too powerful. In fact we have enormous white populations in the American heartland who fear the cities on the coasts and already think that Jews, blacks, and Muslims are both too numerous and too powerful.

In fact, the United States is approximately 13% black, 2% Jewish, and 1% Muslim (depending on who’s counting).

Labels: , , ,

Wednesday, December 13, 2006

Honor Roll

A local suburb, Needham, has decided to stop publishing its High School’s honor roll in the newspaper. Is that a good idea? An article in the local paper explains the reasoning:
“We’ve collected valuable data on the issue,” [High School Principal Paul] Richards added. “One aspect of the work is to examine ways in which the school, as an institution, might contribute to student stress by its traditions, practices, and other actions. The publishing of an honor roll has been identified as a potential contributor to the focus on grades.”
So why is it OK to publish athletic achievements— and music and drama — but not to publish academic ones?

Labels: ,

Tuesday, December 12, 2006

The Supremes

I’m shocked (but not really surprised) that nobody on Jeopardy the other night knew that Earl Warren was the Chief Justice of the United States for the Supreme Court’s Miranda decision. Isn’t that part of being a well-informed American citizen? Maybe it was because all three contestants were native-born Americans; if they had been naturalized citizens, they probably would have known.

Labels: ,

Monday, December 11, 2006

Homework, oral traditions, and religions

Many questions can be raised concerning homework, such as why it is given and what its purpose is. I’ve discussed these big issues in an earlier post. Here I just want to mention a smaller but still significant issue — quantity. Then I want to discuss in detail another significant issue — timing.

In general, I observe that many students in honors courses seem to be spending too many hours of their life doing homework, whereas most students in college-prep classes seem to be spending too few. While those are overly broad generalizations, they are largely valid, at least at Weston. A majority of honors students — not all, but still a majority — are busy with lots of honors and AP courses, sports, activities, music and/or drama and/or dance. And they still want to get all their homework done. A majority of college-prep students at Weston — again not all — still have the sports, activities, and athletic endeavors, but are taking a less demanding academic load. More important, their homework load is lower and they aren’t so compulsive about getting it done. The consequence is that we end up with an inequitable quantity of homework. It would be interesting to see what would happen if we tried to reduce the homework obligations for honors classes and increase them for college-prep.

The principal timing issue is the possibility of no-homework nights. Personally, I would have no trouble with a blanket policy of not assigning homework on any weekend — how’s that for a radical proposal? — as long as it was announced a year in advance. But I have problems with the idea of proclaiming special-case no-homework nights, such as at the end of a quarter or on a Jewish holiday. Here are somes problems that can arise from prohibiting homework on any given night:
  1. Many teachers plan (and announce) assignments well in advance. Needing to postpone an assignment can throw a monkey-wrench into plans, especially when we're bumping up against holidays, ends of terms, etc. No matter what policy a school has, teachers need to be given notice for the following year, not the following week or even month.

  2. In some courses — especially high-level honors and AP classes — the calendar can be very tight, and the course can’t be completed successfully without giving daily homework.

  3. Schools with a complicated cycle, such as Weston’s eight-day one, have de-facto constraints on when tests can be given in certain courses. For example, Day 6 is the only day when the three sections of our Honors Precalculus all meet — and if Day 6 falls on a Wednesday, when periods are shorter, the test can’t be given until the next Day 6. So that means that it might be necessary to give an assignment on an otherwise undesirable night.

  4. Part of the oral culture of Weston High School is that some people think there’s such a thing as a “no-homework weekend” at the end of each quarter and over all vacations and breaks. Maybe this is true at other schools as well. Maybe other schools really do have no-homework weekends. I’ve discussed this belief with various people at Weston, and none of us can find anything in the Student or Faculty Handbooks that recognizes such an event. As far as I can tell, it arose because there really used to be no-homework weekends here — but they went away about twelve years ago. Nevertheless, they seem to linger remarkably long as part of the institutional memory here. Many kids swear that a teacher has told them that I “can’t” assign homework at certain times, though when I hand them the Student and Faculty Handbooks they are unable to find any evidence to support their claim. I think it has just become an urban legend at Weston High School. In this connection the religious holiday issue is especially troubling to me. It’s inappropriate for a public school to recognize one religion over another, and yet that’s what happens when we are told not to give homework over a Jewish holiday but it’s OK to give it over a Muslim holiday. To my mind that just promotes anti-Semitism. I recognize the necessity of the legal fiction that the reason we don’t hold school on Jewish holidays and Good Friday is that they are “days of traditionally low attendance” — for example, faculty absences would be significant on Jewish holidays but not on Muslim ones — but blanket homework prohibitions are offensive because they inevitably favor one religious group over another. Of course we need to be understanding and considerate when students have family obligations, but that should be on a case-by-case basis: a Hindu holiday here, a Jewish holiday there, a funeral in another case. Students have all sorts of family obligations, and religious ones should have neither more nor less status than others, especially when religions are treated unequally.

Labels: , ,

Sunday, December 10, 2006

End in Tears

I recommend the latest novel in Ruth Rendell’s long-running Inspector Wexford series, End in Tears, at least if you’re familiar with some of the earlier installments. (This would probably not be the best introduction to Wexford and his colleagues.) As always with Rendell, this one focuses on complex characters in a traditional “cozy” setting, but there are many more plot twists than is usual in her books. Some reviewers found that the number of coincidences and red herrings caused them to lose their suspension of disbelief, but that didn’t happen to me. Read this if you’re a Rendell fan.


Saturday, December 09, 2006


Many documentaries are Serious with a capital S. Wordplay is lighthearted, as befits a film about crossword puzzles. If that sounds boring to you, don’t watch it. But for those of us who like to cross swords with crosswords, Wordplay is fun and definitely worth watching. The principal subject of the film is New York Times crossword editor Will Shortz, well known in certain circles as the host of the long-running Sunday puzzle on National Public Radio’s Weekend Edition Sunday. Shortz appears as himself — well, it’s a documentary, so all the characters in the film appear as themselves — as do other even more familiar figures, such as Bill Clinton, Ken Burns, Bob Dole, and Jon Stewart. Wordplay focuses on the American Crossword Puzzle Tournament, which may not sound very interesting to many viewers, but of course it’s really about the people, not about the crossword puzzles or the tournament itself. Or maybe I should say that it’s about the competitors, not the competition. Go see it. You may not remember it a year from now, but you’ll enjoy watching it.


Thursday, December 07, 2006

DHS Open House

Come to the Dorchester Historical Society Holiday Party on Sunday, December 10, 2-4 PM, at 195 Boston Street, Dorchester, for food, entertainment, a sales shop, and an exciting raffle. “It’s always a good time,” observes DHS president Earl Taylor.


Wednesday, December 06, 2006

The Keep

The Keep is an unusual, slightly surrealistic novel by Jennifer Egan. I can’t reveal the main gimmick because it would introduce a spoiler, but let’s just say that everything is not as it seemed in the first chapter. In the tradition of Christopher Priest’s wonderful and haunting A Dream of Wessex, it’s not clear what’s real and what’s imagined. Both settings — in both books — are so vividly written that either could be real and either could be imagined.

OK, I realize that that isn’t very clear. But it’s hard to be clear about The Keep without giving something away. This book is part Gothic, part mystery, part historical novel, and part dream. I suspect that it’s the sort of book that you will either love or hate, with little possibility of anything in between. If this brief description piques your curiosity, give it a try.

By the way, there are some serendipitous themes in common with The Rule of Four, which I wrote about last week. For example, both of them involve mysterious journeys through underground tunnels, beneath a university in one case and beneath a castle in the other. And both involve a book within a book. But enough said...


Monday, December 04, 2006

Two more railroad shows

Over the weekend I squeezed in two more model railroad shows. The Marlborough one was OK, but disappointing. The Roslindale one was definitely worth while. Both will repeat in future years, so if you’re interested in model railroads I recommend the latter but not the former.

In Marlborough I attended the National Model Railroad Association HUB Division, New England Model Train Expo, which had a couple of good layouts and a lot of commercial vendors. Mostly it was the same set of products over and over again, from table to table. There was almost nothing that I hadn’t seen elsewhere. There were too many commercial vendors and not enough artistry. Most disappointing was the lack of realistic detail in the layouts: while I don’t expect strict adherence to prototype (a.k.a. “rivet-counting”) in a show like this, I do think that scenery and structures should at least show a little attention to realism. We need the willing suspension of disbelief, as they say in the English classroom. And did I mention that there were too many commercial vendors?

Roslindale was a different story altogether. The Bay State Model Railroad Museum, a merger of the Massachusetts Model Railroad Society and the Bay State Society of Model Engineers, holds an open house several times a year. Packing four layouts into a small space, they are almost the opposite of what I saw in Marlborough, showing attention to detail at every level. The terrain, the scratchbuilt urban structures, the trolleys, and the weathering of all structures and railroad cars were particularly impressive. But so was everything else, really. Check out the links at the right edge of their webpage under Scale Layouts. And go visit them at the next open house, on March 3 and 4.


Saturday, December 02, 2006

A Prairie Home Companion

Just saw A Prairie Home Companion, the late Robert Altman’s star-studded movie about Garrison Keillor’s wonderful radio show of the same name. And star-studded it truly is, with a cast that includes Meryl Streep, Lily Tomlin, Kevin Kline, Virginia Madsen, Lindsay Lohan, Woody Harrelson, and my classmate Tommy Lee Jones. And all of the regular crew is there as well; those who listen to PHC will recognize the names of Sue Scott, Tim Russell, Tom Keith, Rich Dworsky, Robin and Linda Williams, and of course Garrison Keillor himself. But what we recognize, of course, is their voices, since on radio we can only imagine them. Keillor says that he has a face made for radio, and maybe some listeners think that it would be better if it stayed there — but they would be wrong.

Roger Ebert, as he does so often, says it best:
What a lovely film this is, so gentle and whimsical, so simple and profound. Robert Altman’s A Prairie Home Companion is faithful to the spirit of the radio program, a spirit both robust and fragile, and yet achieves something more than simply reproducing a performance of the show. It is nothing less than an elegy, a memorial to memories of times gone by, to dreams that died but left the dreamers dreaming, to appreciating what you’ve had instead of insisting on more.
What’s odd is that the reviewers, including Ebert, didn’t perceive the theme of the movie to be death, but to my mind that’s clearly what the theme was. I have just learned that Robert Altman himself said that this movie was about death — shortly before his own death, hmm... — so now I’m all the more convinced.



This page is powered by Blogger. Isn't yours? Made with Macintosh