Good news for frogs

Good news for frogs: Simulations and ecology are replacing dissections in high school bio labs. The North Jersey Record reports:

Much of today’s academic inquiry has moved to sophisticated studies at the cellular and molecular level, far more complicated than simple anatomy. Moreover, in some classrooms, computer simulation has replaced traditional dissection because it offers not only lessons in anatomy but experiments in physiology, too. In addition, the very reason behind dissection — comparative anatomy — has been overshadowed by the much bigger emphasis in today’s high school biology classes on ecology and the environment.

Some students refuse to dissect out of sympathy for animal rights. New Jersey lets students opt out of dissection labs; they can do a virtual lab or just look at plastic models and write a paper.

Some teachers say dissecting teaches more than the alternatives.

“It allows students to feel the delicateness of the tissue and to appreciate the complexity of a living thing,” said Patricia Lord, science adviser for Teaneck’s schools, where high school bio classes used to dissect earthworms, frogs, perch and fetal pigs but now do only one species a year. “They can inflate the animal’s lungs using a pipette to see how lungs work. They can unravel the intestine to see how long it is and how it’s packed in. There’s so much to learn that way, and they’re always amazed.”

While high school students are dissecting less, younger students are doing more.

Teaneck fifth-graders dissect a pig heart when they study the circulatory system. Tenafly seventh-graders dissect frogs. In Alpine, seventh-graders dissect earthworms, crayfish, fish, frogs and chickens.

Via Teachers Magazine’s Web Watch.

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Comments

  1. Some schools have also been replacing physics experiments with computer simulations thereof: rolling virtual balls down imaginary inclined planes instead of real balls and real inclined planes.

    This all kind of misses the whole point of science, which is that you can *find out for yourself* rather than believing what somebody else (or something else) tells you is the truth. In a sense, it’s a return to the medieval way of determining scientific truth: “Let’s go look it up in Aristotle.”

  2. I agree with David Foster. Why should a child believe a frog has lungs without really seeing them? How can educators who talk about constructing knowledge replace real experiments and dissections? Can’t we teach our students to be skeptical?

    There is an argument that kids do not learn much from dissection and experiments. They might be too traumatic or too expensive.

    But…

    Do kids really learn any better from simulations and pictures?

    How does the cost of providing computers, training and support compare with real experiments and dissections? I think someone is comparing the cost of buying software with the cost of a lab without considering the complete life cycle cost of computers.

  3. Just to clarify, I do believe that simulation can be useful in education…if (a)the real experiment is run and compared with the simulation results (b)the simulation is not a black box, ie, the students can see how gets its results. (For example, a simple spreadsheet calculating the effect of gravity on a ball rolling down an inclined plane.) This would give kids a real basis for understanding what is really going on when mathematical models are used to forecast various things (like climate)

    However, it is very unlikely that such use of simulation will be common in today’s public schools–we are much more likely to see glizy game-like simulations with highly-textured balls running down highly-textured ramps, but with no way to see behind the curtain.

  4. wahoofive says:

    I don’t believe the “animal rights” argument for a second. Students just don’t want to dissections because they’re yucky. But David’s right that real-life experiments are essential in science.

  5. Wayne Martin says:

    Using computer simulation, or other alternative approaches makes a lot of sense. Here are a couple of links worth checking out:

    Frog Dissection Kits:
    H t t p : / / http://www.froguts.com/flash_content/index.html
    H t t p : / / frog.edschool.virginia.edu//
    h t t p : / / froggy.lbl.gov/

    There are far too many experiments that teachers might be interested in exposing their students to that are financially beyond the scope of virtually every school. But with simulation, the essence, if not the actual experiment, can be delivered into every school and home vis-a-via multimedia methods.

    Why does a frog have to be dissected at school in order for a student to become acquainted with the problem, and the goals of the experiment? If the overview were to be presented at school, students could just as easily dissect the frog at home. In the grand scheme of things, what makes cutting up a chicken for dinner that much different than dissecting a frog for a school project?

    While contriving an experiment is important, there is no reason that students have to cut wood, nail it together in order to build a ramp in order to measure the effects of gravity on a ball. Thinking the experiment through mentally is far more important. Keeping accurate records of the “experiment” so that conclusions can be drawn later is not denied students just because the frog, or the physical apparatus of an experiment, is replaced with a “virtual” environment.

    Being able to change experimental parameters quickly is provided in the “virtual” environment. This is not always true in a non-“virtual” environment.

  6. Doing physical science with real materials makes me appreciate what inventors have to do to come up with something that works. You’ve absolutely got to pay attention to the details or it won’t work. And after we’ve removed yet another opportunity for kids to think about problems on their own we’ll whine about needing special “critical thinking skills” in the curriculum. Evidentally, realizing that you chose too large of a nail to be moved by the small current flowing through your wire doesn’t count as critical thinking, but filling multiple choice questions on a worksheet about “the environment” does.

  7. Physics simulations, which I use are actually a godsend. I have short time to complete a “traditional lab” and this helps us experiment and change variables quickly and see the results. We do not do “out of the box” labs (many real world labs are just as lame).
    Another benefit is, in electricity, I don’t have to run to Radio Shack every night and replace components. Students can build circuits and test them and if the component blows then replace it. We also do real circuits, so don’t worry.
    In biology, my daughter just did a tapeworm dissection. I wondered why it was so late in the year. This post answers that question-she has done a lot with molecular biology-which without any chemistry is kinda odd.
    Her comment on the one student who refused to dissect is duh, it is already dead. I agreed and of any animal to dissect, the tapeworm is probably deserves it the most.

  8. My father taught Biology to college freshmen for three decades, and he relied heavily on labs, including dissections. However, there is a problem with frog dissections, and with dissections at all in a highschool class that only gets one shot at it – doing it right with such a small animal is beyond the skill of most students, so they don’t learn what they are supposed to. As my son put it, all he learned was that frogs are full of “frog goo” – amateurish attempts at cutting up the frog left no identifiable organs. My experience with frogs in Jr high and high school was quite similar, even though I had been in my father’s lab many times and quite well understood how it was supposed to work. But animals large enough for unskilled hands to dissect without making a mess of it cost too much, and apparently so did good scalpels and the other instruments needed for a proper dissection.

    Cut up a chicken for supper instead? I have raised, killed, and butchered chickens, and helped butcher venison, and even chickens are large enough that it’s not very difficult to separate the organs (and quite necessary to take some of that out in one piece). You would need a chicken that’s actually whole rather than the usual supermarket “whole chicken” with the body cavity already cleaned and selected organs in a little bag – “dissecting” that would be like learning archaeology from a museum gift shop next to the dig or electronics from assembling Walmart products. I think that doing your dissection on your supper would require starting with a live chicken, because meat doesn’t keep if the lungs and intestines are left in place. It’s both inconvenient and rather traumatic for squeamish kids if the lab has to start with “kill a chicken”.

    Dad’s labs used whole animals, killed and pickled in formaldehyde. Mostly these were fetal pigs, which are a byproduct of slaughterhouses; old sows that aren’t producing so many young get sent to make sausage, and sometimes there are a few more fetuses inside, so the slaughterhouse preserves them in formaldehyde and sells them to a Biology lab supply company. I don’t expect the supply of these would be large enough for high school labs, even if the budget would cover them.

    So I think the bottom line is, you ought to do dissections, but if the school can’t afford to do them right, it may well be best not to do them at all. And of course, nobody forces college kids to take Bio 101 and cut up dead animals – they can choose another class to cover that “science” slot in the distribution requirements – but in K-12 some sort of Bio is always a requirement. (Of course, if you’re in a Bio, Pre-Med, Nursing, or related college major, you’d just better get used to doing such things…)

  9. Wayne Martin

    I think cost, time and safety are good arguments for simulation. But whose costs? I am sure it is easier on the teacher’s budget, but is it cheaper for the school to provide the computers, software and support? Ten years ago I read that a networked computer costs $10,000 per year in support costs in a business environment. I thought the figure was too high then, but I think they are still expensive tools.

    If you do not know the difference between, “cutting up a chicken for dinner that much different than dissecting a frog for a school project? “, I think you missed something essential in biology.

    It does not take construction of a wood and nail incline to make an experiment on uniformly accelerated motion.

    Mental processes are important, but reality is even more important. Aristotle was a great thinker and scientist, but he still got a lot wrong. His errors misdirected the world for centuries.

    A simulation is not an actual experiment. All it shows is what the software is programmed to do. Virtual environments are not real environents. If you teach simulation and experiments are the same or equivalent you are misleading your classes.

  10. wayne martin says:

    > A simulation is not an actual experiment.
    > All it shows is what the software is programmed to do

    This response makes no sense at all. Of course software is “programmed” to do something, but the ability to insert random variables provides a well-designed lab experience provides many new insights into how a physical system might work under conditions that are not likely.

    Given a simple experiment in say, harmonics, that one might see in a high school physics lab—how many of these experiments ever end up disproving the basic laws of physics? My guess is that the number is about zero. So, if software happens to do exactly what mother nature is “programmed” to do – what’s wrong with that?

    (With the software, by the way, you could change the planetary mass so that you could simulate how this experiment would look on the Moon, on Mars and Jupiter. You could also muck around with the gravitational constant and investigate how gravity would look to an observer in such a universe. The more traditional rack, spring and ball apparatus would not provide such a capability, most likely.)

    > It does not take construction of a wood and nail
    > incline to make an experiment on uniformly
    > accelerated motion.

    It was just an example. It does take some physical apparatus .. if even using a tree or convenient overhang.

    > Ten years ago I read that a networked computer
    > costs $10,000 per year in support costs in a
    > business environment. I thought the figure was
    > too high then, but I think they are still expensive tools.

    I’ve never seen a number as high as $10K per PC quoted from a reputable source (or at all). Of course, if a business (like Google, say) were to invest heavily in server farms as a part of its business model, then costs become difficult to predict.). (Workstations that were connected to mainframes were a different beast, however, and $10K could have been easily possible.)

    My school district is quoting Mac-style PCs at $2K for 4-6 years. Network support is not included, but these costs are very low for organizations that provide minimal server (disk storage) support. Internet access (bandwidth) can be expensive, but these cost have become very low in many places. The appearance of WiFi has reduced the cost of network support to servers, Access Points, various software and some on-site support.

    I would be surprised to see the per-station cost for a PC at much more than $750/year (if that). Of course, the cost of instructional software has to be added in at some point. This cost needs to be seen as an alternative to staff costs, which is very expensive. The US is current spending over $400B for educational staffing costs. Any costs for the hardware and software needs to be compared to the staffing costs for the same activities.

    Whether or not PCs can ultimately replace labs is an open question. Keeping in mind that public schools cost between $750-$1000 per square foot to construct (and finance), and some number of dollars per square foot to maintain over the life of the building–per foot costs for schools probably run in the order of $1500/square foot per 30 years. Reducing these costs with much lower cost hardware/software should be a goal of every school administration.

  11. tsiroth says:

    We dissected fetal pigs in my junior year Anat & Phys class in high school. The class had four maybe five sections, and pigs were one per pair of students. Much easier to dissect fetal pigs than worms or frogs, I assume. But then, in my whole high school and junior high, there was never any dissection except the fetal pig dissection in this one A&P class. My teacher was also able to get a cat for those of us who wanted to come after school. The cat dissection was certainly helpful when I did cat dissection again in college.

  12. SuperSub says:

    It’s surprising that amongst all the clamor for authentic, hands on activities that students are motivated to perform, that dissection labs are cut. Less than 5% of students, from my experience, have any problems with participating in dissections. Of course, I do offer alternatives, but ones that are as difficult as the actual dissection. Many of the simulations that I’ve seen are significantly easier and quicker to do than a real dissection, and I’m confident that many students who request simulations do so because of that.
    As for whether the students get anything out of the dissection, my class’ dissections of fetal pigs generally last 4-5 lab classes. We focus on one or two systems at a time as the anatomy allows. Students do gain an appreciation and awareness of their own bodies due to the dissection.
    I’m currently looking into doing a pithed frog lab sometime in the future.

  13. Wayne Martin

    I now understand that you do not accept the difference between a simulation and reality. I learned long ago to flee anyone who blindly believes computer output. We do not have much more to discuss. But…

    The point is not to disprove the Laws of Physics, but to demonstrate them. You only demonstrate them by showing the forces of nature at work. You do not demonstrate them by getting the out put of functions on a computer simulation.

    Your fiddling with a few parameters on planetary orbits you cannot verify is not science. It is merely playing. Firing a howitzer at a target to verify your simulation results is science. I have actually done it. How has your class verified your simulations? Using a simulation without verifying it is just like reading Aristotle and believing his theory of matter.

    I attacked your example of wood and nails as a poor reason to avoid doing an experiment. Now you agree with me?

    The $10,000 figure was from a Gardner Group report and it made big news in the business press way back when. These were PCs connected to servers, not mainframes. Some attacked the way it was computed, but there methodology seemed sound, but the cost struck me as high by 50%. I would guess that 20 percent of the $10,000 was depreciation. I do not think that is part of a school district’s accounting system. Do you have any complete costs figures from your school district to refute them? Accounting is all about how you assign costs and the Gardner Group knows more about this than me. How do you know if your district is not burying costs in some other category, like personnel costs, warranty costs or utility costs?

    “Reducing these costs with much lower cost hardware/software should be a goal of every school administration.”

    I must be dense but I do not see how computers and software lower these costs. I know they have increased the cost of occupying the building I am in. I know of 3 buildings that were cheaper to completely tear down and rebuild than to try to upgrade them to back fit them with more modern networks and computers.

    Have a nice day.

  14. I teach science to very young children, but a common upper elementary school dissection is an owl pellet – easy to get, and without any killing involved. There are “virtual owl pellet” websites that sort of simulate the experience, but it isn’t the same. I also do flower and fruit dissections with my youngest classes – less controversial but very, very informative. But the purpose isn’t to help 6 year olds develop their surgical skills – I do all of the knife wielding, and they manipulate and touch and observe and draw and label.

    As for simulations in general, to me they serve a limited but important purpose. I use them when we’re learning about something that can’t be experienced or experimented with directly – for example, we aren’t going to be taking any field trips to a hydrothermal vent anytime soon, but the kids have very much enjoyed the “virtual dives” we’ve taken through interactive websites. (We did a similar “virtual field trip” when we were learning about black holes.) There are some ecosystems that lend themselves to terrariums, of course, and we’re doing those too.

    I want the kids to understand that programming and running simulations is one way that scientists in different fields test hypotheses. I give them my computer speech – something to the effect of “This program/website/whatever is only as smart as the person who programmed it. The programmers included everything that they thought was important, but if there is something that they don’t know, it won’t be in here.” But, that speech also applies when we look at printed information. The information in a science book is only as accurate and current as the author’s knowledge (or the sources’ knowledge) when it went to press. Students have to learn to evaluate the sources of information that they encounter and how to integrate that with what they’ve experienced directly.

  15. Alex Bensky says:

    Well, it’s nice to know that fewer frogs will have to croak to advance science.

  16. Lab experiments for students are not to demonstrate scientific concepts. A canned videotape, or preprogrammed simulations, don’t prove anything. At best, they’re the equivalent of videotaped textbooks.

    The greatest value in requiring students to perform labs is to teach them to observe, and to learn how many variables can influence a lab’s outcomes–in the real world. Are your values off? Why? Is your lab partner flummoxed by stopwatches, perhaps? Or did you set up your ramp at the wrong angle?

    Simulated “labs” are great if you want to teach science appreciation. If you want scientists, however, you need real labs.

  17. Wayne Martin says:

    > The point is not to disprove the Laws
    > of Physics, but to demonstrate them.

    Which is what simulation software does. What makes you think that it doesn’t?

    > Your fiddling with a few parameters on planetary
    > orbits you cannot verify is not science.

    I suggested planetary masses, which are fairly well known. However, you miss the point again. If you make the claim that no knowledge can be gained from simulation software, you are not doing your students (or the taxpayers) the justice they deserve.

    > You do not demonstrate them by getting the out put
    > of functions on a computer simulation.

    So I take it that you would not fly on a 747 whose pilot has trained extensively on a 747 simulator? Do you feel that CPR exercises should not be performed on a dummy—since dummies aren’t “reality”?

    > The $10,000 figure was from a Gardner Group report
    > and it made big news in the business press way back when.

    Maybe.. “way back when” costs probably shouldn’t be introduced into a discussion about “here and now”. (Out for a bike ride, it dawned on me that the IBM AT was introduced at about $6,000 [basic configuration] around 1985. Apple had introduced the Lisa around 1982 for about $10,000. While the Lisa was just too expensive at that price, the AT’s found customers. Prices came down quickly as competitors got into the game. That was twenty years ago.)

    With most PCs in the $600-$1000 range (and a $100 LapTop in the wings), it’s time to use prices which we are all looking at today, on-the-shelf. (Yes, synchronous 3270 workstations connected to IBM workstations were very expensive. Even early general LANs were not all that inexpensive.) Having purchased a lot of hardware for startups, $10K a year per PC would put a small company (less than 100) out of business before it got started (that comes to $1M per 100 employees per year, by the way.). Sever costs have come down to $100K-$250K for very capable servers (capable of multiple terabyte capacities), these days.

    > I know of 3 buildings that were cheaper to completely tear down
    > and rebuild than to try to upgrade them to back fit them with
    > more modern networks and computers.

    Most buildings have a 30-50 year lifecycles. It’s not at all uncommon to hear that a Public Works/Facilities group claim that they can’t do this, that or the other unless they tear down the building. Government generally does not like to maintain its buildings. (One estimate that I saw for a proposed library in my town was $5K per Ethernet drop. This cost included conduit cost, labor to run these conduits and pull the cable through them. If the cost is allocated against the workstation, this might drive the cost up somewhat.) Cheaper techniques almost never seem to be included in the cost of public facilities. Many public buildings are still not designing network support with WiFi yet. By the way, what about rehab/retro-fit costs for ADA building access/bathrooms, A/C, roofing, plumbing and electrical service up-to-code and dual-pane windows? Any of these other items fit into the “cheaper-to-rebuild” decision?

    > Do you have any complete costs figures from
    > your school district to refute them?

    Unfortunately, no. This particular school district hides almost all of its technology costs outside its published budget. Some of the hardware has been purchased by gifts from parents. Some has been donated. Sadly, there is no unified software/hardware budget. At the moment, I don’t believe they could answer your question.

    > How do you know if your district is not burying costs
    > in some other category, like personnel costs, warranty
    > costs or utility costs?

    I have reviewed many of the financial records of this school district for a couple of years. It was from this exercise that I came to understand that the district did not have a unified technology budget, and could not provide any accounting whatsoever for cost. Through public records requests I did get some piecemeal costs, such as PC cost and replacement cycles, however.

    Software can increase the cost of a computer system quite a bit, but the cost offsets have to be considered in order to make any sense out of the computer costs. Failing to understand the cost offsets makes this picture hard to understand.

    > I attacked your example of wood and nails as a poor
    > reason to avoid doing an experiment.

    Most lab experiments require some sort of apparatus. This equipment costs money to buy (or build), must be maintained, stored, inventoried and moved to/from a storage facilities. Much of this equipment can be emulated (or simulated) on PCs very effectively, providing less work for lab teachers. Software that can be site-licensed at the District (or County level) will ultimately reduce costs.

    > Now you agree with me?

    No .. you have missed every point that has been made.

  18. Wayne Martin says:

    > Lab experiments for students are not to
    > demonstrate scientific concepts.

    You can’t really mean this? Did you mean to say something else?

  19. Wayne Martin

    We will never agree.

    A computer simulation is not different from a magic trick. You do not see what is really happening. A simulation is simply the behavior of the equations in the textbook, not a demonstration of the phenomena. Math and Physics are related but not the same subject.

    The $10,000 was from approxiamtely 1995.

    The 3 buildings I am referring to are privately owned. I suspect that the complications of real estate depreciation and taxation provided the financial incentive for their destruction.

    If I had to choose a pilot with 10,000 hours of real flying with no simulation or 10,000 hours of simulation with no flying I would choose the pilot who really flies. I would prefer they trained on aircraft and simulators, with simualtors that mimicked the aircraft.

    I would be better at CPR if I had worked on real people and not just the dummy. The dummy was better than nothing.

    They train experienced test pilots to fly the on the 747 simulator then they put him in the prototype to make sure the 747 flies as it was intended. They validate the simulation and the aircraft before they fly passengers and train aircrew. Your students don’t see proof the simulation mimics nature. They only see the simulation mimic what they are taught. You do not appreciate the difference.

  20. If one wants to educate scientists, one does not want to produce a group of people who will look at a simulation, and say, “oh, of course. I see. Gravity. What a concept.”

    One wants a group of people who will say, “Why? Is it always true? If I do the same things, will I get the same result?What if I do this? What makes it change, and how? Is there anything I have overlooked? How could this result be disproved? Is it true everywhere?” One does not want people who will take anything on faith. One wants people who will say, “I don’t believe you. Can you prove it? Huh. That’s neat. But if I change this, it doesn’t happen. How do you explain that?”

    A simulation does not demonstrate the laws of physics. It demonstrates its preprogrammed responses. Any randomness is generated from a defined algorithm. It’s like the choose-your-ending books popular for beginning readers.

    If a demonstration were sufficient, there would be no need for lab courses. The instructor could perform the exercises in a theater; scientists in training could observe by closed-circuit t.v. That isn’t sufficient, just as a textbook isn’t sufficient.

  21. wayne martin says:

    This statement:

    > The 3 buildings I am referring to are privately owned.
    > I suspect that the complications of real estate
    > depreciation and taxation provided the financial
    > incentive for their destruction.

    is quite different than originally claimed:

    > I know of 3 buildings that were cheaper to completely
    > tear down and rebuild than to try to upgrade them to
    > back fit them with more modern networks and computers.

    > One wants a group of people who will say,
    > “Why? Is it always true? If I do the same things,
    > will I get the same result? What if I do this? What
    > makes it change, and how? Is there anything I
    > have overlooked? How could this result be
    > disproved? Is it true everywhere?

    And the use of simulation/multimedia tools in the Lab deny teachers and students access to this key part of the education process how? This software is just a tool, and it’s a poor workman who blames his tools.

    > A simulation does not demonstrate the laws of physics.
    > It demonstrates its preprogrammed responses.

    Well, I guess it’s time to dredge up our ole’ friend Bill Clinton, and ask what the definition of “demonstrate” is here.

    > Any randomness is generated from a defined algorithm.
    > It’s like the choose-your-ending books popular
    > for beginning readers.

    Views like these are far too parochial to characterize the power of well-designed software.

    > If a demonstration were sufficient,
    > there would be no need for lab courses.

    Not necessarily. However, it would be possible to provide a fully functioning multi-media instruction segment that would provide the same experiences that are now provided in a brick-and-mortar lab.

    > The instructor could perform the exercises in a theater;
    > scientists in training could observe by closed-circuit t.v.

    Closed-circuit TV redistribution has been replaced with WEB-casting—but the idea is the same. Lots of schools (mostly in the 3rd world) adopted this methodology starting in the mid-80s.

    > That isn’t sufficient, just as a textbook isn’t sufficient.

    Not certain why—just design a text book that contains all the material needed for a student to teach him/herself. With on-line access to instructional materials, fewer teaching hours could be applied to the problem of mass education than now.

    In the mid-80s a fellow by the name of Jim Blinn gave a presentation at a symposium that I attended which featured some of this work at JPL in graphics. Within a year or so, this work was incorporated in a very interesting work called: The Mechanical Universe:

    http://www.learner.org/resources/series42.html

    I spent a number of hours looking to see if this series were on-line. I was pleased to see that it is, at Annenberg/CPB. This series has been on PBS any number of times, and is scheduled to be broadcast again in the fall of 2007. However, after registering on the site, the series is available to folks with a broadband connection right now.

    This multimedia tool provides video and animated graphics which offers “simulation software” to the student. This work is now over 20 years old, but still is very useful for introducing physics to students.

    I have found perhaps upwards of 75 links to WEB-sites which provide video segments to physics labs, and simulation software that offers “demonstration” and on-line exercises to allow students to demonstrate their mastery of the subject. There were a couple of WEB-sites which also provided a good example of the AP physics instruction. The following seemed good for this discussion:

    AP Physics at BHS (Batesville, IN) Laboratory Index:
    http://www.batesville.k12.in.us/physics/APPhyNet/lab/APLabIndex.htm

    (Sorry about drifting in a topic on Physics, but the underlying issues are the same.)

  22. Wayne Martin,

    What I suspect and what I know do not necessarily contradict. I was told the reason for the buildings destruction was the tenants wanted them upgraded to support more information technology. The owners response was that it was cheaper to destroy and rebuild. They did not just gut the interior. The collapsed the buildings, carted off the rubble, drove new piles, laid a new foundation and built new buildings in their place. I can only speculate about the role of taxes and depreciation since I never saw the accounts and tax records of the building’s owner and do not have an accounting or real estate background. I usually assume in our society that expensive private undertakings happen because they make financial sense.

    I can state with confidence that the power, security, wiring and cooling improvements in my organization’s floors to support the increase in computers, security, printers and servers increased the cost of our lease. I also know that 5 years from now the building we occupy will be torn down and rebuilt. I assume that means building will depreciate to zero in 5 years. I do not know, I do not own the building. It could also mean the owner just wants to tear it down and rebuild because he felt like it.

    I do not dispute that animation and simulation have educational value. I do strongly believe they are not a substitute for actually seeing the phenomena when practical. I do believe simulations can be used to extend experience in unsafe situations and lower training costs but they are not a substitute for hands on experience.

    I enjoyed the Mechanical Universe years ago and watched it many times. I think it has great value to students. I think it does a great job illustrating physical principals, but I think very little of it verifies the phenomena it was using to illustrate the laws of Physics. In my opinion it is not a substitute for lab work. Still I would rather have a student learn Physics without a lab or even without simulation than not learn Physics at all.

    Lets move away from Physics. Consider the frog dissection. Amphibians can have lungs, internal gills, external gills, or lack both gills and lungs, during different phases of their life cycle. Why should a simulation of a frog’s dissection be accepted as evidence for a frog having lungs? The Dusky Salamander and the Pigmy Salamander both lack lungs and gills in their adult terrestrial form. Why can’t a silent frog?

  23. wayne martin says:

    > Consider the frog dissection. Amphibians can have lungs,
    > internal gills, external gills, or lack both gills and lungs,
    > during different phases of their life cycle.

    OK.

    > Why should a simulation of a frog’s dissection be
    > accepted as evidence for a frog having lungs?

    There seems to be a real “trust”/”faith” issue here with computer-based laboratory/education software. As someone with four decades of computer product development, I find this sort of incredulity difficult to understand. We have been virtualizing “reality” for decades. Look in your wallet—see very much money? Probably not. But I’ll bet that you’ll find a bunch of credit cards. Are those plastic cards money? No—but they certainly spend like money, don’t they?

    And if you do have some bills, look at them. Are these silver or gold certificates? No—our folding money hasn’t had anything of value behind it for decades; however, those depository certificates are accepted world-wide.

    What about those little dots on the air traffic controller’s screen. Why should anyone believe that those little dots represent aircraft at their correct altitude and velocity? Particularly if they can’t believe that a glyph in a graphics rendition of a frog’s lungs might be there without actually being in the frog.

    We are surrounded by “virtualizations” everywhere we go. How in the world can educators claim that virtualizations have no place in their domain by questioning the relationships of the symbols and the physical entities these symbols have been chosen to represent?

    If you want to claim that we are teaching the “scientific method”—which assumes that you don’t know the answers to the questions you are asking and that you shouldn’t trust anything unless you actually “touch” the apparatus and take the data yourself—then perhaps you’re pushing the envelop just a bit for a high school environment.

    Looking around on the WEB, there are a number of Virtual Frog Dissection programs/kits–

    Dissecting a Virtual Frog:
    http://fas.sfu.ca/newsitems/dissecting-a-virtual-frog/

    Like most students, Vafai had to dissect a frog in high-school. “But I didn’t learn anything,” she says. The frog was small. She could not “zoom in” as she can with her virtual frog, and she had partners, so not everyone had the experience of dissecting. “If you cut something wrong on a real frog, you lose,” says Vafai. With the virtual frog, you just hit “Restart” and try again.

    Virtual Frog Dissection Kit:
    http://froggy.lbl.gov/virtual/
    http://froggy.lbl.gov/

    UVA/Netfrog:
    http://www.isoc.org/HMP/PAPER/135/html/paper.html
    http://frog.edschool.virginia.edu/

    http://www.froguts.com/flash_content/demo/frog.html
    http://www.froguts.com/flash_content/index.html

    Obviously there are a goodly number of people in the profession feel that virtual dissections are a good idea.

  24. wayne martin says:

    > The Dusky Salamander and the Pigmy Salamander
    > both lack lungs and gills in their adult terrestrial form.

    Well designed software could provide information about how the oxygen is absorbed through the skin, since these species evolved without lungs. Since some salamanders have lungs, opportunities exist for comparisons between the two species that demonstrate how oxygen is absorbed into the creature’s bodies.

    Educators should be looking for opportunities to use these tools to increase the number of educational experiences for their students, rather than nits over details such as being offered here. Nothing being discussed is not already in place. Students all over the US are using these tools today. They will only get better in the future.

  25. Wayne Martin

    We use radar for air traffic control not to virtualize it, but because radar can detect aircraft further than human vision and see though bad weather and the dark. It is better than human vision for air traffic control. It is “trusted” because it is calibrated regularly by professionals Even then operators must be aware of the possibility of false echoes and spoofing. In WWII the Japanese optical systems could detect our warships in the dark better than our radars, look up the First Battle of Savo Island. Operators deceived by radar are still a problem today even though we depend on it so completely. We take aggressive steps to make radar as trustworthy as possible. How do they take steps to make virtual dissections trustworthy to students? This is science we are talking about, where reality is always placed higher than authority, theory, history or precedent. Trust and faith are not terms usually associated with Science. I realize students cannot experience or see every thing you try to teach, but virtualizing what they can directly experience is a terrible idea. This is not about teaching the scientific method as much as putting reality above pictures, simulation, text and authority. The history of science is filled with people looking at the same phenomena or anatomy and seeing and finding something no one has seen before. Don’t you think it strange that with all the people looking at animal and human anatomy for centuries that parasitism was such a late discovery?

    People not understanding the difference between cash and credit is a big problem in this country. I think your example is a bad one.

    Your economic examples are flawed. Haven’t you noticed inflation and deflation of paper currencies throughout history? We have simulations of the economy and market transactions that no one can believe. Remember that economic theory is about rational people making transactions with knowledge not prejudice, panic and lies. Economic meltdowns happen far more frequently than our economic simulations predict.

    The relationship between symbols and reality is an excellent issue, but a frog and its anatomy are not symbols. Students need to understand that. When ever you use symbols in place of reality you need to have some idea where the symbolic manipulation will mislead you.

    My personal experiences with dissection have been good, Just because something does not work for some is not a good reason to eliminate it for everyone. How does cutting wrong on a dead frog make you lose? Cutting a live frog incorrectly could. Using a simulator to prepare students for real surgery on an animal makes sense to me. Using simulation to reduce error, risk, decrease cost and increase safety is frequently a good idea.

    Even though there are a lot of advocates for simulation. At no point in this discussion has anyone showed that students learn better from a simulated dissection that a real dissection. We can always find some who will say one is better than the other, but are you aware of any data? I suspect that we can find a lot of students who did not learn well from either approach, and this had nothing to do with the dissection or simulation.