Wednesday, July 26, 2006

Ideology Trumps Reality - Again

This is old news but it turned up in an Edutopia newsletter I received today. I skimmed the story last week about a U.S. Dept. of Education (read Bush Administration) study that showed no significant difference in educational performance between comparable private schools and public schools. No surprise there, really. But somehow I missed (darned skimming) the story behind the story. Wow. It's just hard not to fall into a pit of despair at the sorry state of affairs in this country under Bush & Co. Just follow these two headlines:


July 15, 2006

NY Times


Public Schools Perform Near Private Schools In Study


July 18, 2006

NY Times


Republicans Propose Nation-Wide Voucher Program



The first headline actually understates the issue - in all measures except 8th grade reading public schools performed better than comparable private schools. How the Times translated that into "public schools perform near private schools" is beyond me. So much for the liberal NY Times.

The Edutopia Newsletter links to an editorial in the Palm Beach Post:


Bush-Supressed Study Dispels Voucher Myth



The focus of this editorial is the story behind the story, but I will go back and quote from the original Times article to make the point:

Its release, on a summer Friday, was made without a news conference or comment from Education Secretary Margaret Spellings.


...


A spokesman for the Education Department, Chad Colby, offered no praise for public schools and said he did not expect the findings to influence policy.



And then juxtapose that absence of comment or fanfare from Ms. Spellings with the announcement of the voucher proposal:

With Education Secretary Margaret Spellings joining them in a show of support, Congressional Republicans proposed Tuesday to spend $100 million on vouchers for low-income students in chronically failing public schools around the country to attend private and religious schools.


Another salient point is that the Bush administration sat on this report for almost a year and added commentary to the report in an effort to soften its impact.


As an isolated event, this sequence might not be so earth-shattering in the grand scheme of things. But this administration shows time and again an utter disregard for reality in formulating and carrying out public policy and we've got 2+ more years to put up with it, if we all live that long. (OK. That's a bit over the top. All this talk about Armageddon, I'm starting to develop a complex.)

Tuesday, July 25, 2006

It Pays To Complain

In the previous post I complained about the lack of support from HP for a computer I own that needed a new hard drive. Getting the hard drive isn't the problem, but installing the operating system was. HP (& many other manufacturers today for unknown reasons) does not ship recovery CDs with their new systems. Instead, the operating system is located on a special section of the hard drive (a "partition") so you can reload the OS from the hard drive if needed. That's all fine and dandy if your problems are software related and you just want to wipe everything out and start over with a clean slate, but when the hard drive fails, you're screwed. In theory you can order recovery CDs from HP (at about $50.00 with shipping & handling - a scam itself since you already paid once for the OS when you bought the system!) but HP has apparently "run out" of recovery CDs for my system and can't be bothered to burn a few more CDs - how hard can that be? Anyway, That's where I am. A big heavy CPU that will have to be thrown in the garbage because HP can't burn a measly CD that would make it work again and I decided not to throw down $100.00 for a new copy of Windows XP.


I sent a letter of complaint to HP after several failed attempts to get a copy of the recovery. The people at their online tech support were very nice and supportive but they didn't apparently get the memo about recovery CDs, so twice I was informed that the CDs were available, twice I submitted all the relevant info about my computer and personal information, and twice I waited for a phone call to finish the order only to be informed (twice!) that the CDs were not available. I won't even mention the time before these two attempts when I called HP sales directly and was told the CDs were not available. OK, I mentioned it.


I had pretty much given up when a phone call from HP (in response to my e-mail) informed me of a third party vendor who could supply me with the recovery CD and that HP would reimburse me for the cost. Now I just have to cross my fingers that it actually works.

Monday, July 24, 2006

Time for Work

At least I'm not alone in my summertime "procrastination." I've spoken to many an other teacher with similar stories. I have this long list of things to do for next school year and here it is near the end of July and what have I got done?


Well, actually one way I procrastinate is by working hard on tasks that I hadn't consciously planned to work on. The workaholic in me just won't let me have a real day off, so I piddle around doing odd jobs that do need to get done but were never on my list of priorities until I needed a diversion from the things that were on it. For example, it's amazing how much household chores and daily maintenance activities can pile up when you're working 10-12 hours a day during the school year. Several closets were nearly inaccessible with junk and winter clothing and boxes. My office was a wreck. Papers piled up and needed organizing, books that have long since lost any possible relevance littered the shelves and need to be gotten rid of. My computer hard drive was equally in need of organization. I had thousands of digital photographs, for example, that needed to be copied onto CDs before they disappear forever from some hard drive failure or something, and most of those photos exist in duplicate forms scattered across several directories and a couple of hard drives - so that beast needed to be tamed. I also spent a couple of days trying to figure out how to get another computer running (for one of my kids) that had a hard drive failure last year, a computer that is no longer supported by HP. These dastardly computer companies no longer ship recovery CDs with new computers and this one's out of warranty, so the only solution is to buy a new hard drive and purchase a new copy of Windows to load, and I can only imagine the problems I will run into and the hours I will be online with tech support after I spend that money for the materials. It's a real scam that I have to pay again for an operating system that I already paid for. I sent an e-mail to the HP CEO expressing my displeasure.


Of course I've also spent some time "vegging out" for lack of a better term. This past year was emotionally draining, especially the end of the year. I really needed a couple of weeks to just clear my head. Most of that time has been spent exploring some new music and adding to my mp3 collection. For the record I listen mostly to indie "fill-in-the-blank" - indie rock, pop, folk, art-rock, whatever. I've posted a few "Friday Random 10" lists if you're curious. I get a lot of information from Pitchfork. I don't always like what they like, but I can frequently tell from the reviews whether I will like a band or not. Sometimes I just put on Yahoo's LAUNCHcast "radio" and hit the next button until I hear something I like. Then I check out other music by the same group. I also mentioned in a previous post that for the first time in my career teaching I have a few students who's musical tastes overlap with mine, so I've got a lot of recommendations from them that I've just now had the time to listen to. Why is commercial radio in New York City so awful, by the way?


My actual goals for the summer are to get ready for the fall in a couple of ways. I"m looking at what was difficult last year and the year before and coming up with some strategies. Some problems that I thought were attributable to the particular school I was in before turn out to have traveled with me. For example, my students' inability to keep up with their lab reports. That turned into a nightmare again when, despite my constant repeated refrain that students MUST keep their lab reports as a "ticket" to the exam, they still came to me in May acting like they were receiving this information for the first time. And in a way they were - They never really processed what I was telling them. It's like the one or two times I've almost run a stoplight while staring right at it because my mind was pre-occupied. So I have to figure out, for my own sanity, how to deal with this requirement.


In a related item, I'm working on having lab binders prepared for students in the beginning of the year. I can't stand the constant runs to the copy machine to get worksheets done on an almost daily basis. The issue will be storage space and student access to them. I don't have the kind of students that I can depend on to carry their binders around, so I'll have to store them. I don't think it will be that much of a problem. I've got a good space for them, then it's simply a matter of establishing routines to ensure a smooth delivery and return.


I will be streamlining labs and breaking up the bigger ones to accommodate the lab schedule in my school. Many of my labs have a tendency to soak up time like a sponge, and that leads to incompletes and lack of closure and "when can I finish it" and so on. I have what I consider to be a bare minimum number of periods per week for the LE curriculum - in fact, it's a real stretch and a rush to get through the material that I want to get through, so I have to minimize inefficiency. I also have an incredibly diverse (academically) group of students in every class. I'm looking into a tiered approach to as a way of differentiating instruction, which I'll address in a separate post after I've worked out the details.


I think I'll end with that, as this is getting a bit long. I'm starting to feel the energy again and need to get to work!

He Started It!

He Who Cast the First Stone Probably Didn’t


NY Times



I think all teachers and parents know about this little quirk of human behavior and psychology. An argument ensues in your classroom and if you take the time to try to mediate the conflict and figure out how to resolve it, you can easily get caught up in an endless regression into who did what first to whom that sometimes goes back several periods, days, even years as student A recounts how student B teased him in first grade.


I've been thinking about this a lot lately as the violence in Lebanon/Israel escalates, and even made a passing reference to it in conversation yesterday when asked about my feelings on the situation. Lo & behold the NY Times has an article citing research on the "he started it" phenomenon and applies it to - you guessed it, the conflict in the Middle East. The term "even-numberedness" refers to the idea that it's OK to strike back (physically or verbally) at someone who has harmed you.
That’s why participants in every one of the globe’s intractable conflicts — from Ireland to the Middle East — offer the even-numberedness of their punches as grounds for exculpation.


The problem with the principle of even-numberedness is that people count differently. Every action has a cause and a consequence: something that led to it and something that followed from it. But research shows that while people think of their own actions as the consequences of what came before, they think of other people’s actions as the causes of what came later.


It gets worse. Another feature of conflict is the magnitute of the response to a perceived "punch." Retribution in kind is generally perceived as "fair," but an excessive response to a perceived wrong ("an eye for an eye-lash" as the Times puts it) is generally not. So researchers set up an experiment to see well we can gauge the fairness of our own actions.

In a study conducted by Sukhwinder Shergill and colleagues at University College London, pairs of volunteers were hooked up to a mechanical device that allowed each of them to exert pressure on the other volunteer’s fingers.

The researcher began the game by exerting a fixed amount of pressure on the first volunteer’s finger. The first volunteer was then asked to exert precisely the same amount of pressure on the second volunteer’s finger. The second volunteer was then asked to exert the same amount of pressure on the first volunteer’s finger. And so on. The two volunteers took turns applying equal amounts of pressure to each other’s fingers while the researchers measured the actual amount of pressure they applied.


You can probably guess the results. The pressure escalated as each mis(under)estimated the force he/she was applying to the other. With each round of retribution the pressure increased even though each participant believed that he/she was giving back in kind.


I think this article might be a good point for discussion in my classes this year.

Saturday, July 22, 2006

NASA’s Goals Delete Mention of Home Planet

NASA’s Goals Delete Mention of Home Planet


Wow. Is there any limit to this administration's naked ambition?


OK. I did just see "An Inconvenient Truth" but come on, after the recent uproar over a politically appointed NASA officer trying to censor NASA scientists from speaking publicly about global warming data, they simply delete any reference to our terrestrial home from the mission statement? OMG.


David E. Steitz, a spokesman for the National Aeronautics and Space Administration, said the aim was to square the statement with President Bush’s goal of pursuing human spaceflight to the Moon and Mars.



...so that we might establish a new home after we've destroyed this one?


Realated storys:


Censorship Is Alleged at NOAA



Just Added (7-29-06)


The FDA Is A Cauldron of Discontent


A recent survey of FDA scientists:

The researchers' answers portray a culture of discontent where scientists report not having enough resources to properly evaluate products, having scientific results ignored, being pressured by political appointees to approve drugs and--most criminal, considering the FDA's mission--providing misleading information to the public.

You can research the whole study at:


Union of Concerned Scientists

Wednesday, July 05, 2006

Back To The Blog Again

And to kick things off, this story from the New York Times, which I'll link to, but it won't be available for long before they take it down and charge for it.


Bronx Sixth Graders Master Mysteries of the Biology Regents


I'll quote:



Although the biology Regents is usually taken in ninth grade, teachers at this school felt that their students needed a challenge, so they essentially started teaching ninth-grade biology and added test preparation.

Ten of the 23 students who took the exam (known formally as the Living Environment test) passed with marks between 65 and 80 on a 100-point scale. Of the 51,000 students who took the exam citywide in the 2003-4 school year, 58 percent passed.



Ten out of 23 students passed a 9th grade exam in 6th grade. The article says they completed 20 hours of labs, apparently mostly on Saturday extra sessions. Sounds impressive? Well, actually 20 hours is the bare minimum required to qualify for the exam. What did they do in the other periods? What happens to the 13 who didn't pass the exam? If they couldn't score 65 on a generously scaled (i.e., curved) exam then what exactly did they learn? How much confusion was sown, how many kids came away feeling that science is just too hard for them?


I don't mean to sound so negative, and I'm sorta happy for the kids who passed the exam. I'm sure they feel a good deal of pride. I do wonder about kids feeling pride in achieving a 65 on an exam and thinking that this is an "accomplishment." I graded a fair number of exams and a 65 on the exam, while passing, shows an incredible LACK of understanding of the mysteries of biology. I had a number of students pass with scores in the 65-75 range and I just had to shake my head at how little they knew. What really bothers me is that this approach to teaching is more about the school than the kids. There are so many other ways to make a science program rigorous and at the same time age-appropriate.

Sunday, March 05, 2006

Sporadic Turns To Hiatus

My already sporadic posts are about to be even more so as I wind down the school year and get more and more swamped with my masters project. This will be the last post for some time.


My students are working on their carbon autobiographies, with varying degrees of success. Some are really taking off with it, delving into the details of all the processes that happen as a carbon atom cycles through the environment. Others are dragging their feet or doing a strictly mechanical job of complying with the minimal requirements of the assignment with little enthusiasm. I totally understand, on the one hand, and would myself probably be the kind of student who couldn't get into this project much. On the other hand, it REALLY highlights just how fragmented their knowledge is - they really struggle to put the pieces together into a coherent narrative and I think that makes it a valuable exercise. Below I outline some of the problems with this assignment, but the students' problems start way before these issues even come up - for example, they totally gloss over the photosynthesis and respiration parts, which they are expected to know at this point.


Here's a basic description of the project, Carbon Project, which I keep revising as I run into complications. Some of the processes are rather complex and I will make revisions again for next year. For example, cellulose synthesis is not completely understood and the only literature I can find on the web is highly technical and beyond a high school student's comprehension, so I've had to summarize some of it for them. Similarly, the digestion of cellulose in cows is a complex process. I originally used pigs, but that's even more difficult to figure out. I have taken the more complex parts and simplified or summarized for student in class, they just have to weave the science into their stories and find appropriate images to accompany the stories.


Elsewhere, my masters project is about teaching/learning evolution. Here's my basic premise. The conceptual change model, which I think is a useful one, suggests that students come to us with existing conceptions about how the world works. A typical example is the "naive" conception that summers are warmer than winters because the sun is closer to the earth in summer and farther away in winter. If we ignore this naive conception, we will get the student in class to parrot what we say about the tilt of the earth and all that, but in a short time or with a little pushing, we will find that they really still hold on to their original beliefs. Conceptual change models suggest addressing student pre-existing ideas up front, setting up inquiry activities that produce cognitive dissonance (where the naive conception breaks down), then offering an alternative (scientific) schema that explains the phenomenon better. That's it in a nutshell.


So how do we apply this model to the teaching of evolution? Inevitably this approach will lead to bringing religious discussions into the classroom since many students prior conceptions about origins of species (especially human) will come from religious stories. My preliminary research suggests that most teachers are not comfortable approaching evolution in this way, but the consequence may be that we are "covering" evolution in class but our students are coming away with not much understanding to show for it. My plan is to in fact have this discussion with students, offering them a range of options for how do deal with any conflicts between their personal (religious) beliefs and evolution, and investigate how their understanding of evolution is affected by this approach. I actually began thinking about this last year, and I posted a few comments about it here. I've got lots of details to work out so I should stop procrastinating NOW and get on it.

Monday, February 20, 2006

Burnout

Edwize has a post on teacher burnout and KIPP-like charter schools. I've wanted to write a similar post but I'm no expert on the subject, and my opinion would be little more than conjecture based on hearsay about how these schools operate. I could add my general experience with a number of teachers who come into the system from various special programs (I wouldn't want to single one of them out) with unrealistic work ethics and rather large turnover rates.


The basic problem, before I go to far off topic, is that these schools have a high turnover rate for young and energetic but inexperienced teachers. They are driven, both by personal passion for their work and by the culture of their schools to work excessive hours - on a daily, weekly, and yearly basis. This level of work is impossible for most people to sustain given the intangible and often negligible benefits of their efforts - i.e., their personal gain (financial) is not commensurate with the level of effort, and the gains by their students are not much different than their more experienced colleagues working more efficiently. From Edwize:

The school hires energetic and well-meaning, but young and completely novice teachers. It then has to employ ‘teacher proof’ curricula and extend the ‘on time’ into the evening in order to compensate for the lack of teaching skill and experience. Teaching needs to be reinforced by a school culture which leans toward the authoritarian. By the time a teacher would ordinarily have begun to acquire the knowledge and skills that allow her and her students to work smart as well as hard, she has burnt out, and is unable to maintain the intensity of work. It is also impossible to start a family with such a work load.


I'm neither young, nor particularly energetic or bright, and I'm not working at a KIPP school, but I do teach within a school culture with a strong work ethic. And I am a bit overextended as I've mentioned in earlier posts. The pace of work that started the school year has not subsided, the demands of my job still have me working on average about 10-12 hours per day (5 days per week - I'm averaging in weekend hours) and a lot of it is precisely the inefficiency you would expect to find in new teachers - scrounging around for activities and labs, gathering materials for labs, setting up materials, creating quizes and tests that are appropriate for the regents curriculum, helping students make up missing work, etc. I can easily see myself next year chopping an hour or two off the average workday and at the same time being a better teacher.

Sunday, February 12, 2006

Blizzard

Second biggest snow storm in NYC history, according to NY1 News.





"The first blizzard of 2006 is only inches away from breaking the record. The city received at least 24 inches of snow, making it the second biggest snow storm in city history."


The good news is that it happened on a weekend with lots of warning, so the city hopes to be up and running by Monday morning. Still, should make for an interesting school day, or week even. I'm scheduled to visit (observe) a fellow living environment teacher at another school on Tuesday. I hope that doesn't get postponed or cancelled- these things don't just happen and my AP has been working on the arrangements for a few weeks now.


As far as teaching goes, we are into the human body systems, working our way toward reproduction and genetics in a couple of weeks. As a review of several concepts, I have the students working on one of those hokey assignments that I usually avoid, but decided to give it a go for this unit. They are writing an "autobiography" of a carbon atom beginning in the atmosphere as part of a CO2 molecule then cycling through plants and animals and back to the atmosphere. Along the way they will have to discuss plant structure & photosynthesis, animal digestion, circulation, cellular respiration, and excretion. Not to mention the implicit review of biochem concepts including chemical bonds and enzymes.


I had this feeling that students simply weren't getting the whole carbon cycle concept - in fact, making sense of a lot of the abstract ideas in biology is a stretch for a lot of my 8th and 9th graders. And honestly, I try to keep it at a level necessary for the regents. I do not feel compelled to turn regents LE into AP Bio. Of course, it's not always easy to read the tea leaves and figure out exactly how much is enough for the regents exam. I'm hoping this will help a little. If I get a chance I'll post a fuller description and a rubric sometime this week.

Wednesday, February 01, 2006

Dads-to-be pile on the pounds too

I knew there would have to be an evolutionary explanation for all that weight I put on when my wife was pregnant. Of course the study involves monkeys and has not been applied to human fathers-to-be, but now it's my story and I'm sticking with it until proven otherwise!


In studies on two groups of monkeys, marmosets and tamarins, both small, monagomous primates, the father to be gains 10% of his body weight during the mate's pregnancy.


The males' weight gain is probably a result of their producing greater levels of prolactin – the same hormone that encourages milk production in the females. “Our earlier studies showed that prolactin levels increase in males halfway through pregnancy, when the females experience a hike in corticosterone – a hormone involved in sending and receiving pheromones,” she adds.


A couple of caveats regarding the application of these results to humans. First, increased prolactin level alone is not a associated with weight gain in humans. Secondly, prolactin is associated with good fathering practices in some other animal groups but a direct link in humans and other primates has not yet been verified


It would be great to look at hormone levels in good and bad fathers but it’s very hard to get the data on men who abandon their babies...


As for me, I put on about 5% of my weight during the pregnancy and another 10% afterward - something tells me my excuse isn't going to hold up to scrutiny.

Friday, January 27, 2006

Regents Question Analysis

Some of my students get really freaked out by the kinds of questions that are asked on the regents exams. As I mentioned earlier, they expect the questions to be familiar and frequently I hear things like, "we never learned that," or words to that effect. They work themselves into a state of panic when the answer isn't immediately obvious but rather requires some thinking and problem solving process to figure out. I try to alleviate their stress by doing practice questions and looking at strategies, but every time I give them a test with regents questions on it, they go through the same conniptions. In they end, they don't do as badly as they think they did, in part due to the regents curve that I apply to those types of tests, and in part because they don't realize that they can actually figure out the answers if they don't give up so easily.


So, today I'm having them produce regents question analysis posters, as a review of both the process of figuring out the answer and as a review of some of the content covered by the most recent test I gave (cells/cell processes). Here's a model of what they will produce on paper ( I did it on powerpoint, which you can download.) I kept the explanations simple and short, so don't get nitpicky about the details.


Tuesday, January 24, 2006

Homo troglodytes

Welcome to the family, chimps & bonobos? There's a movement afoot to bring the remaining members of the Pan genus under the Homo umbrella, according to an article in the Guardian. It has long been known that these two species have more in common with us Homo sapiens than with the other great apes and more and more genetic evidence/evolutionary evidence seems to support the reclassification. The latest evidence indicates that humans and chimps have similarly long generational timeframes (the length of a "generation" is similar) going way back in our evolutionary history and the extremely long time between human generations has apparently long been an argument for our "special" taxonomic status apart from the other great apes. The new study shows that humans and the Pan species have had similarly slow rates of genetic mutations, indicative of long times between generations. It has long been known that humans and chimps have a common ancestor not shared with gorillas or orangutans, so it has long made little sense from an evolutionary perspective to think of the "great apes" as one group and humans as a separate group.


I say it's only a matter of time before the facts overtake tradition and politics - the sooner the better.


UPDATE


This article from National Geographic, Chimps Belong on Human Branch of Family Tree...(dateline 2003), discusses the issue of reclassification in a little more detail and points out some of the difficulties, among them the confusion that can arise from the domino effect - reclassifying chimpanzees into the genus Homo would necessitate the renaming of several fossil hominids that have been assigned their own genera.

Regents Week

Not for my students, of course, but a large number of students are taking January regents this week which means proctoring and marking papers and getting in grades and continuing to teach my 8th grade class (middle school students are in regular session all week). Actually a couple of my students are in fact taking a "make-up" regents (Earth Science) due to failure to get a 65 or better in June or August, but not that many.


I had this morning "free," as in free from "teaching" a class, but I didn't even break for lunch and worked straight through from 7:30 this morning till 6:00 this evening grading projects, lab reports, & tests, and checking homeworks in preparation for semester grades. We should have a regular work week where the students once per week come in at noon (I'm much more productive in the morning) for a half day of instruction to give teachers a block of paid time to check student work or otherwise be productive in ways the board of ed refuses to recognize as meaningful labor on our part. It's a sign of what they think we really do (babysit) that they only want to consider us as "working" if we are in front of a group of students giving a lesson. I'm reluctant to use the more general term of "teaching" to describe that activity, because I consider the time I spend marking student work as teaching. Not to mention the time planning. The time collaborating with other teachers. The time consulting with parents. The time spent in faculty meetings. Etc.


OK. I didn't start this post as a rant, so I'll stop now. We are really starting to get into the meaty part of the curriculum and a lot of students are struggling. There's something more or less intuitive and easy about ecology, where we started the year, but as we get into cell processes it gets abstract very quickly and I don't think a lot of students know quite how to deal with the level of understanding they need for the regents exams. They seem to be groping around for a list of vocabulary words or simple processes or rules they can just memorize. I gave a test on some cell basics, culled from old regents exams. The results weren't impressive. I did allow them to use their books but warned them they probably wouldn't find the books very helpful - since the regents exam requires them to pull together bits & pieces of information from various parts of the book, and apply what they know to novel situations - the answers aren't in the book, they have to be synthesized in the brain. I actually made them work without the books for about 15 minutes, answering questions as best they could, then allowed them to open the books. I may do something similar in the future and find a way to compare their open book answers to their closed book answers to see how much they actually change. Hey, I might even be able to turn that idea into my master's project, with some refinements.


Speaking of master's project, I may have to put that off for another semester. For some reason that class is always in demand and filled to capacity with a waiting list, and I wasn't able to get in. I am on the waiting list, but I won't be that upset if I have to wait till next fall, when I'll have a better grip on my curriculum and materials and will not, I hope, be working 10 hours a day on a regular basis.

Sunday, January 22, 2006

Evolution in the City

In response to a comment to this post from a reader in Kansas, I thought I'd share my sons' experience with evolution in a NYC public school.


My 2nd grade sons (twins, neighborhood public school) just went on a field trip to the Darwin exhibit at the American Museum of Natural History. The whole second grade went and I was sort of expecting to hear some backlash, but so far so good. This was entirely their teachers' idea and had nothing to do with me. They did read a children's book on evolution in class before the trip as preparation - (Our Family Tree: An Evolution Story, by Lisa Westberg Peters). The book was my wife's idea and she loaned them our copy. But I was impressed that the teachers organized and carried it out without much fuss or fanfare. I asked my sons about it afterward and they seemed to actually get the major concept of natural selection, through a computer simulation at the exhibit in which the background color changes over time and the color of a population of prey organisms changes with it. "When the background is green the orange bugs get eaten by the birds and when the background changes to orange the green bugs get eaten." I pressed them a little further and asked what was left when all the green bugs were eaten, and they told me that only the orange bugs were left. Pretty good summary for 2nd graders. I hope my 9th graders get it!

Saturday, January 21, 2006

Friday Random 10 Moved

Not that anyone noticed, but I've moved the Friday Random 10 posts to a new blog to which I can refer students, which I'm calling Past Redneck. I have continued the tradition, and it looks like PZ Myers is back on track at Pharyngula (no connection). By the way, Pharyngula has moved to a new hosting site designed just for science bloggers, and powered by SEED magazine.

Know Your "Cell-f"

The big idea I want to get across is that our cells are essentially a microcosm of us. The things that we need as individual organisms are the things that each of our cells needs individually. The food and oxygen we need to take in, the waste materials we get rid of, the temperature we maintain, and so on. Reproduction takes place ultimately at the level of the cell. I've extended it to the idea of friendship, even. We as individuals depend on our friends and social networks for survival, so too do our cells need each other. No cell is an island, so to speak.


I haven't any particularly new ideas these days and not much in the way of new material - we just did a rinky-dink lab looking at onion and cheek cells under a microscope. It's the kind of lab that I despise but I needed a filler as I don't have an alternative yet. As I've mentioned before I like labs where students are trying to answer a question by measuring or otherwise collecting numerical data and I don't have anything that involves making a wet-mount slide and then looking at the cells for some variation that we can quantify and correlate to another variable. I can think of some possibilities but I haven't had time to sit down and test them out or develop a lab around them.


One idea is to take for example a green onion and look at the different parts of the onion - root tips, bulb, green tips - to see if there is variation in the average size of the cells in these different parts (I'm pretty sure this is based on another lab I've seen somewhere looking at the different stages of mitosis in the different parts - but that requires complicated staining techniques if I remember correctly, or prepared slides). My reasoning is that parts that grow faster (root tips?) will show a smaller average size because there will be more of them at different stages of mitosis - the daughter cells initially being smaller than the parent cells. How would we measure the size? I noticed in our labs that 100x magnification of onion cells gives us a nice, easily countable number of cells within the field of view. A greater number of cells within a given field of view means a smaller average size obviously. If you've done this kind of lab or know of links to a version of it on the web I'd like to know. I could be totally off and there are probably other variables that affect the size of cells in the different parts of the onion that would make a conclusion impossible to draw, so I would really need some time to go through the lab myself to see if it's feasible.


On to human body systems and maintaining homeostasis.

Saturday, January 14, 2006

Eggs Again

I posted about this lab last year, and I've since revised the lab sheets. This year I used some food coloring for the different corn syrup solutions to help keep straight which dilution was which, then collected the eggs in a jar to represent a collection of cells and demonstrate the idea that the cells in our bodies are bathed in fluid into & out of which materials flow. I should have added some tubing to represent the capillaries, but I thought of it after the fact and adding the tubes would likely have burst the fragile eggs, creating a horrible mess.




I like to do this lab even though it replicates some of the concepts in the Diffusion Through a Membrane required lab. The eggs are of course a good size to work with and I'm always partial to labs where we can measure the results and graph the data. They also respond pretty consistently and dramatically to the different soultions, making them virtually foolproof if the kids measure correctly (and the eggs don't break - always plan extras). The occasional broken egg adds to the "ick" factor. The basic strategy is this:


Students weigh the eggs before soaking in vinegar. This is the baseline mass that we use for comparison after it soaks in the other liquids, so we are investigating how the egg deviates from that original mass (we ignore the mass of the dissolved shell since it is pretty trivial compared to the overall mass of the egg and the changes we get from osmosis.) We can estimate the original water content (%) in the egg by interpolating from the graph the point at which the change in mass would have been zero - the point where the line they graphed intersects the y x axis. The point where the line intersects the y x*axis represents the point at which the concentration of water inside the cell would be equal to the concentration of water outside the cell. Needless to say the kids get a little confused with the terminology and using a graph in this way. There are a couple of tricky mathematical components to the lab, but all age/grade appropriate - it's just the kids are used to doing math in math class and apparently not comfortable applying the skills to science class. Aside from the graphing, a few kids were uncomfortable subtracting a large initial mass from a smaller final mass (final mass - initial mass) to get a negative change. We also did not simply use the change in mass, since the eggs were all somewhat different sizes in the beginning, so we calculated the % change to control for that variable (thanks to Mathew Davies, my G-K12 fellow last year, who helped me revise the lab).


You need at least 4 days for this lab,longer if you let students soak all the eggs in the various solutions. It is possible to check the eggs at the beginning of the period and have some time left to do other things afterward. You may need to refresh the vinegar after the first day. The eggs don't seem to suffer from leaving over the weekend if you have to start in the middle/end of the week. Have lots of paper towels. I've estimated the water content of corn syrup solutions, but the numbers may be off - something about the nutrition label doesn't make sense, and I got conflicting numbers from the USDA as to the sugar/water content of corn syrup, so check those numbers for yourself if you're concerned about the accuarcy of the details. It's bothersome to me but I can live with the rough estimates.


*I meant the y=0 point, which is actually the x axis. Sorry 'bout that...

Friday, December 23, 2005

Wasted Time

All my plans of course went out the window for the week with the strike. Most classes were at 5-10 kids all week, so I let them catch up on missing work or do some regents review work from one of the review books we have at the school. Today is anybody's guess - strike is off but it's Friday after 3 days of no school and the day before holiday break - will the kids be bored from staying at home and all show up today, or will they say screw it, it's Friday, and stay home again?


Either way, Friday Random 10 goes on. Here's my list from the week, this time actually taken from my mp3 player (portable), so it's newerish stuff that I actually listen to, but again it's getting time to download some newerer material.


Artist Track


1.U2......Beautiful Day

2.Pixies......Gigantic

3.Pearl Jam......Light Years

4.Snow Patrol......Raze the City

5.Ocean Blue......Between Something & Nothing

6.Interpol......NYC

7.Weezer......Island in the Sun

8.Radiohead......My Iron Lung

9.The Arcade Fire.....Une Anee Sans Lumiere

10.World Leader Pretend......New Voices

Tuesday, December 20, 2005

Intelligent Smackdown

(edited - 3:15pm)


Judge rules against 'intelligent design'


Sorry for the juvenile reaction, but honestly I'm pretty disgusted by the ID crowd, and seeing their little masquerade exposed is just too satisfying not to revel a bit:


We find that the secular purposes claimed by the Board amount to a pretext for the Board’s real purpose, which was to promote religion in the public school classroom...


I grew up with a pretty strong religious belief, and the unethical tactics used by these people would have appalled me even back then - the lying and subterfuge are below the ethical teachings of most religions - that I know about anyway.


via Pharyngula

Strike!

So the Transit Transport Workers Union is on strike. NYC subways & buses are shut down. I have no idea how I will get to work - the city seems intent on making the situation worse, clearly with the intent of making everyone angry and then pointing the finger at the union. Schools are in session in spite of the fact that vast numbers of students and teachers will be unable to get to work today. I work downtown, but driving is not an option - 4 passengers per vehicle are required to drive below 96th street. At 5:00 AM the highways are already backed up as the police literally stop and check every vehicle for the occupancy minimum. It's fricking cold - "mad brick," so riding my bike could be hazardous to my health with icy spots still on the ground from the recent snow & rain.


But I support the union. The press is totally biased, the commentary of the anchors and reporters is laced with subtle and not-so-subtle stabs at the union. The MTA has billion dollar surpluses and is giving away money to the riders, then they want to screw new workers coming into the system - I can tell you that creates a lot of animosity among membership. As a teacher I am still pissed at my union for negotiating contracts in the past that set up "tiers" within the teacher ranks and some tiers have benefits that I'll never get and in some cases teachers had teaching loads lighter than mine - think about that: Inexperienced and overwhelmed new teachers working side-by-side with experienced teachers who have fewer teaching periods per day. It is unconscionable for a union to sell out it's new members to maintain a level of income and working conditions for it's existing members.


Another consequence of the strike is that our lesson study has been cancelled. I don't know at this point if or when it will be rescheduled. Since it is content specific and part of unit study, it would be impossible to just postpone the lesson that we've now spent so much time planning.


UPDATE (9:30AM)


I took a chance on the bike, and arrived at 8:30 to work without incident. I thought I might have gotten frostbite on my toes as the frigid west wind (in my face, more or less) kicked in hard at about 96th street, but an hour later and the pain is gone - worst case of cold feet I've ever had. Temperature around 22F with wind chills in the teens/single digits and worse with bike speeds factored in.