Date: Mon, 14 Jul 1997 20:28:05 -0500 From: Carolyn Sweeney Judd Subject: CJ-Paper9:lab vs simulation Content-Type: TEXT/PLAIN; charset=US-ASCII Harry, In you paper you refer to test results that compare the understanding of students, some of who did the actual experiment and some who did the simulation. My concern with these kinds of comparison is that I assume that the test was administered on paper. Would the results have been the same if the students who did the simulation were tested on the computer. I have suspected that there is a real cross-over problem in learning the material in one medium (computer) and then being tested in another medium (paper.) I know that we have all seen this transference problem with students who capably do an experiment in the chemistry lab, but cannot transfer that knowledge to paper for the exam. I really do wonder about the statement that if "I do something, I will understand it" better than if I only watch. Perhaps that statement only works when the situation is very familiar to the student. Nice paper, with lots to think about. Carolyn Judd Houston Community College cjudd@tenet.edu ------------------------------ Date: Mon, 14 Jul 1997 20:33:55 -0500 From: Carolyn Sweeney Judd Subject: Paper 9 -CJ: Using Simulations after the lab Harry, I have often observed that simulations are enjoyed by those who have already had some exposure to the real thing I think that an ideal situation would be the following order: 1. show a video of the experiment so that the student knows what to expect 2. the student performs the experiment in the chemistry lab 3. the simulation is done after the lab to reinforce and build on the recent experience of the student. Of course, this all takes bundles of time, but I am not at all sure that the students benefits from the simulation unless the mental concept is already there. Are there some simulations that you have used that just work beautifully? Carolyn Judd cjudd@tenet.edu ------------------------------ Date: Mon, 14 Jul 1997 23:46:41 -0500 From: George Long Subject: paper 9: grl - Visualization vs Simulation Harry, One of the things that interested me was the distinction between simulation and visualization. Do you know of any studies that focus on the effect of the degree of interactivity on student learning, or perhaps on thelack of a "visual" interface for the simulator (since I guess a very interactive simulator may just output numbers ? Do you think that a high degree of interactivity between the simulation and the student is best for a simulation, or is the visualization end of things more important for student learning ? George Long IUP -------------------------------- Date: Sun, 20 Jul 1997 16:09:31 -0400 From: "Harry E. Pence" Subject: Pap 9:HEP-Ans. to short Quest.(long) Answers to Short Questions on Paper 9-Simulations Don Rosenthal suggests a change in the definition of simulation: >In defining a simulation (see below) should "uses a mathematical or >logical algorithm" be changed to "uses a mathematical and/or logical algorithm" I considered making the change you suggest, but I couldn't think of an example that used both types of algorithms. Can suggest a case where the and is appropriate? Don Rosenthal also asks >SQ1: Suppose I wish to provide a simulation of the eleven bottle >experiment where a student is given eleven bottles and is told >the eleven reagents these solutions contain. By combining reagents >he is to deduce which reagent is in which bottle. The simulation could >be performed by using computer graphics or photographic images on a >computer controlled video disk. For example, when solutions 1 and 2 >are combined a yellow precipitate is formed. The student could select >solution 1 and 2, which would be shown to be colorless. The solution >would be shown to be mixed and the resulting yellow precipitate could be >shown. >According to your definition would this be a simulation? My definition forces me to call this a simulation, I would feel that this is a very low-level simulation. I feel strongly that a real simulation must allow the user the ability to EXPLORE what happens due to new combinations of variables, not just to confirm values that were already known. The opportunity for the user to explore is minimal in this case. >SQ2: Suppose graphics were not used and the words "yellow precipitate" >appeared on the screen. Would this be a simulation according to your >definition? I believe that an EFFECTIVE simulation must present a sufficiently realistic picture of the simulated event and also a sufficient intellectual challenge to involve the user in the working universe of the simulation. The next step would be to eliminate the computer and have an assistant hold up a card with the word "yellow precipitate" based on a table of instructions. Is this a simulation? My experience is that today's students are too sophisticated to be involved with this situation, and therefore it would not be an effective learning environment. >SQ3: NASA often shows via TV what they call simulations. >Would these be simulations according to your definition? Not unless the "simulation" is presented in such a way that the user can modify conditions and see the results. I would call these animations. >SQ4: Are the terms "reality" and "a simulation of reality" useful >in the context of your definition? I'm not sure of what you're driving at in this case, Don. Can you clarify your question? Carolyn Judd asks My concern with these kinds of comparison is that I assume >that the test was administered on paper. Would the results have been the >same if the students who did the simulation were tested on the computer. >I have suspected that there is a real cross-over problem in learning the >material in one medium (computer) and then being tested in another > medium (paper.) I agree that a paper and pencil test is inadequate to test the kinesthetic component of lab work. Do we believe that this kinesthetic component is essential? We need to clearly define what we are trying to teach in lab, regardless of whether we use simulations or not. Otherwise, we're going to have a hard time justifying traditional labs. >I have often observed that simulations are enjoyed by those who have >already had some exposure to the real thing I think that an ideal >situation would be the following order: >1. show a video of the experiment so that the student knows what to expect >2. the student performs the experiment in the chemistry lab >3. the simulation is done after the lab to reinforce and build on the >recent experience of the student. >Of course, this all takes bundles of time, but I am not at all sure that >the students benefits from the simulation unless the mental concept is >already there. My lecture presentations are similar to what you have suggest. First, I lecture for 10-15 minutes to develop the background, then I do some type of visualization, which may range from a live demo to simulation, and finally I do a cooperative learning segment, so that the students are forced to integrate the components I have presented. I give two brief student surveys per year to observe their reactions, and these consistently show strong support for this method of teaching. For example, I ask my Gen.Chem. students to react to the statement, "The combination of hearing about a concept, seeing a demonstration, and then talking about it seems to be the best way for me to learn." The most recent results (fall 1996) were strongly agree - 60%, agree - 38%, neutral - 2%, with no students answering disagree or strongly disagree. (N = 57) >Are there some simulations that you have used that just work beautifully? The most successful simulations seem to be simple ones based on a spread sheet program. For years I had trouble making some of my students understand the Boltzmann Distribution. Then, I built a simple spreadsheet that allowed me to vary the molar mass of the gas and the temperature, and showed the results as a simple line graph as well as a bar graph. The students have done much better on this topic since I began to use this approach. George Long asks >One of the things that interested me was the distinction between >simulation and visualization. Do you know of any studies that focus >on the effect of the degree of interactivity on student learning, or >perhaps on the lack of a "visual" interface for the simulator (since I >guess a very interactive simulator may just output numbers ? Do you > think that a high degree of interactivity between the simulation and the >student is best for a simulation, or is the visualization end of things >more important for student learning ? Involvement is critical, and the minimal level of interactivity and reality required to involve a student tends to change with time and with the prior experience of the student. At one time PONG was a popular computer game, but I doubt if the current students who are accustomed to more sophisticated games would find PONG interesting. In my paper, I mention that Rieber et al present results that they feel show that simulations produce little improvement in learning for adults. This strikes me as contrary to everything that I have experienced. The simulations that Rieber used were very simple, and I wonder if they weren't too simple to involve adults and produce a useful learning experience. ***********End of answers to short questions. ------------------------------ Date: Mon, 21 Jul 1997 08:16:02 EDT From: Donald Rosenthal Subject: Paper 9 - DR: Mathematical and Logical Algorithms My Short Questions: >> In your paper you indicate that a "a true simulation uses a mathematical >> or logical algorithm to reproduce the selected characteristics of a >> system in such a way that the effect of changing individual variable >> values can be observed." >> I am not certain that this definition would include everything which I >> would consider to be a simulation. (Perhaps I don't understand what you >> mean by a logical algorithm.) It seems to me your definition is rather restrictive. Can you give several examples of what you consider to be mathematical algorithms and what you consider to be logical algorithms. Donald Rosenthal ROSEN1@CLVM.CLARKSON.EDU Clarkson University Potsdam, NY ------------------------------ Date: Mon, 21 Jul 1997 09:27:32 -0400 From: "Harry E. Pence" Subject: Paper 9 - HEP ans to DR: Mathematical and Logical Algorithms On Mon, 24 Jul 1997, Donald Rosenthal wrote: > It seems to me your definition is rather restrictive. > > Can you give several examples of what you consider to be mathematical > algorithms and what you consider to be logical algorithms. Mathematical algorithms are most common and run the gamut from simple spreadsheet programs, where mathematical equations lie behind the cells of the spreadsheet, to the very complex simulations used to represent large environmental systems, like photochemical smog or ozone depletion. Logical algorithms are less common, but the example that immediately comes to mind is the one that you used in your post of short questions. You asked if the 11 bottle experiment could be called a simulation. In this case the controlling algorithm would presumably be some set of expressions that indicate that IF soln. 1 is added to soln. 2, THEN show frame 100. There are algebraic methods for expressing this relationship, but the result is still a simple set of statements that govern the simulation, rather than numerical calculations. Both of these allow the user to explore what happens when various sets of conditions occur. In my mind, if there is less opportunity to explore, the situation is less like a scientific simulation. Does this clarify the definition? Cordially, Harry ------------------------------ Date: Mon, 21 Jul 1997 11:24:49 -0400 From: Brian Tissue Subject: Paper 9 - BT, video game culture I came across an interesting article that is relevant to Harry's paper: Sherry Turkle, "Seeing Through Computers: Education in a Culture of Simulation," The American Prospect no. 31 (March-April 1997): 76-82 (http://epn.org/prospect/31/31turkfs.html). The article described a couple of examples where students used video game skills to successfully perform simulations; e.g., SimLife, SimCity; rather than by developing an understanding of the underlying principles. Has anyone observed similar trends with chemistry simulations? My guess is that this problem becomes more common as simulations get larger and more complex, and farther removed from the mathematical basis. The article also discussed the trend to use computers in education as an "appliance," with less teaching of what goes on "under the hood." The author did not offer any advice concerning this dilemma. Brian ------------------------------ Date: Mon, 21 Jul 1997 15:00:46 -0400 From: Michael Chejlava Subject: Paper 9 - MJC Response to BT Video game culture Brian Tissue asked- >Has anyone observed similar trends with chemistry simulations? I used several Project Seraphim simulations ( Sulfuric acid factory, water treatement plant and oil refinery) and thought I was onto something really good whhen I observed that the students were really involved in these simulations. However, after questioning the students about the basis of the simulations, I found little understanding. They had been "video gaming" these simulations. One common feature of these simulations was scorekeeping. This lead the students to do whatever it took to score without regard for the basis. I no longer use such simulations. I do use the JCE HPLC simulator and after students determine the optimum conditions for separation of a mixture I have them test it on a real HPLC to see how the simulation fits the real world. They can then look for some of the factors that make the simulation different from real life. Thank you for pointing out that paper Brian, it was very interesting. One fear that I have with the use of simulations is that people will use simulations for each individual case and never discover general laws. An example would have been if they had modeled gas molecules in a statistical mechanics way, they would have just kept using the model for different cases and never would have come up with PV=nRT. While this equation is not exact for real gasses, it sure is handy for a first approximation. -- Michael Chejlava Department of Chemistry & Environmental Science Lake Superior State University Sault Sainte Marie, MI ------------------------------ Date: Mon, 21 Jul 1997 15:39:06 EDT From: Donald Rosenthal Subject: Paper 9 - DR: Reality and Simulations of Reality Re: SQ4: "reality" and "simulation of reality >> SQ4: Are the terms "reality" and "a simulation of reality" useful >> in the context of your definition? > Can you clarify your question? Situation A ^^^^^^^^^^^ Suppose a student were to go into the laboratory and perform an experiment to determine the infrared absorption spectrum of gaseous HCl. The instrument provides the vibrational-rotational spectrum. The instrument is computer interfaced and in addition to providing the spectrum it provides a table of peaks and percent transmittances. The student can analyze the data to obtained a vibrational force constant and the interatomic distance. These calculated quantities can be used to calculate the spectrum. This is the reality. ^^^^^^^ ------------------------------------------------ Situation B ^^^^^^^^^^^ Suppose a student went to a virtual reality laboratory in which he "saw" the instrument and associated equipment. He performs the "same" experiment as in Situation A and obtains a spectrum someone has obtained from the infrared instrument used in Situation A. The student performs the same analysis of the experimental data as in Situation A. To the student this may appear very much like situation A. In some sense I would describe this as a simulation of the reality of Situation A. Admittedly, a very realistic simulation (according to my conception of simulations). ----------------------------------------------- Situation C ^^^^^^^^^^^ Like B, except the spectrum is calculated using the force constant and interatomic distance for HCl. Some experimental error may be added to the calculated results. ----------------------------------------------- Situations D and E ^^^^^^^^^^^^^^^^^^ Like B and C except that simple computer graphics are used to simulate the instrument. Control settings are varied, switches are turned on, etc. using either a mouse or the keyboard. ----------------------------------------------- Situation F ^^^^^^^^^^^ The student is told he has performed an experiment and obtained the infrared absorption spectrum of HCl. The student is presented the HCl data obtained from an experiment like that in Situation A. Alternatively, a data bank might be available and the student would be asked to: 1. select a gas (HCl, HBr, HI, CO, CO2, etc) 2. select the wavelength range to be scanned 3. perhaps even to specify additional variables ---------------------------------------------- Situation G ^^^^^^^^^^^ Like F except data are provided from calculations using appropriate force constants and internuclear distances. ---------------------------------------------- In each situation the student performs similar calculations and prepares a similar laboratory report. ---------------------------------------------- MY QUESTION: Which of these situations (B to G) would you regard as a simulation of Situation A? ============================================== Another Question: Random walk simulations have sometimes been used in the modeling of physical and chemical processes. ^^^^^^^^ How would you distinguish between a model and a simulation? --------------------------------------------- Donald Rosenthal Clarkson University Potsdam NY ROSEN1@CLVM.CLARKSON.EDU ------------------------------ Date: Mon, 21 Jul 1997 16:49:03 -0500 From: Sylvia Esjornson Subject: Paper 9: SRE -Author-ity of Simulations Authority of Simulations The authority of a simulation depends on the students' acceptance of and willingness to try to envision the particulate nature of matter in motion. I find that, for many students, even high tech simulations amount to not much more than cartoons, unless the students accept the transfer of author-ity to themselves. I wish to build on ideas presented by Jim Stevenson and Leon Combs, below, to reinforce an idea from paper 6 that the simulation provides a key and that an interactive simulation may be preferred to promote learning. In this I believe I agree with the author of Paper 9 as well. Leon L. Combs writes: We also must always remember that these are models of reality. Students, and others, sometimes tend to accept the simulations as reality which can be an even bigger problem. If they don't see the derivations of the equations then they don't see the assumptions involved which limit the applicability of the simulations. "Nature" doesn't have to solve equations -- we do, because we have to have models of reality. James N. Stevenson writes: Somewhere along the line the student must accept the "authority of the simulation" in order for learning to take place. The student must believe that this is how beams, atoms or molecules actually behave in the world in order for the simulation to be effective. Where does this acceptance enter the process and by what means? 1. Can we rely on the "if it's on TV (computer, web, etc.) then it must be true" axiom (or adage)? 2. What else can be told to the astute student who asks, "How did you make the computer do that?" other than "I used equations, i.e., relationships (Fortran, Basic, C, Java, ....)? The authority of the simulation and the limits of the model concern me here, and I find within Paper 6 an intriguing opportunity for learning about consequences of the particulate nature of matter in motion as presented in Figures 5 and 11 of Paper 6. You may recall: Fig. 5. Simulation of the movement of gas phase argon atoms above a solid surface. As an example of such a simulation, Fig 5 shows the establishment of a concentration gradient for argon atoms above a solid surface under the influence of (very strong!) gravity. collisions are elastic, and that energy is a function of vertical position. Fig 11. A display of a cold gas about to condense to a liquid; pairs of molecules have already begun to form [8]. This is where I find the teachable moment, because in order for the student to accept the authority of the simulation, the student wants to know how strong that (very strong) gravity must be (fig 5), ........ AND- if the experiment would work better if the gas were cold (fig 11). So in a way the student wants to re-write the experiment to see if simulation Fig. 5 was set up to take temperature into account and conversely if Fig. 11 was set up to take gravity into account. If the student discovers that these experiments are independent of gravity or temperature, respectively, or that the effect is small, I count that as learning. A small peek at the code used to "tell the computer how to do that" would be very informative at this point. Interactive simulation programs that include temperature terms and gravity terms could enable the students to see for themselves what effect there is on the system. Students could change the value of the parameter and see for themselves how the system responds. Paper 9 expands on this topic, especially that the learner have an opportunity to influence the outcome. So, to me the authority of the simulation depends on the validity of the assumptions made in the equations which tell the computer how to do that. And no, just because we can show it on TV does not necessarily mean it's true. Actually, some students in my classes are reluctant to accept the idea that, if we could see on the molecular level, the real world would look anything like the simulation, and they dismiss (do not engage with) media presentations as stop gap measures rather than accept them as useful models of reality. One of the learning goals for my class is to have the students understand why we scientists accept mathematical descriptions of the behavior of matter: their basis, their usefulness, and their limitations. Computer simulations at the particulate level are very helpful in showing students that (for the most part) chemical substances obey the equations and by changing parameters, we can influence the state of matter. Sylvia Esjornson, Ph.D. Chemist Assistant Professor of Chemistry Southwestern Oklahoma State University 100 Campus Drive, Weatherford OK 73096 esjorns@swosu.edu (405) 774-7032 ------------------------------ Date: Mon, 21 Jul 1997 18:16:07 -0500 From: sc18 Subject: Re: Paper 9 - MJC Response to BT Video game culture Michael Chejlava wrote: > Brian Tissue asked- > >Has anyone observed similar trends with chemistry simulations? > > I used several Project Seraphim simulations ( Sulfuric acid factory, > water treatement plant and oil refinery) and thought I was onto > something really good whhen I observed that the students were really > involved in these simulations. However, after questioning the > students > about the basis of the simulations, I found little understanding. > They > had been "video gaming" these simulations. One common feature of > these > simulations was scorekeeping. This lead the students to do whatever > it > took to score without regard for the basis. I no longer use such > simulations. > Hi All, This passage describes the "Feynman Effect" which I also discuss in J.Chem. Ed. 1996,73,116 "Computational Chemistry in the First Organic Chemistry Course" We seemed to show in that paper that proper use of formative and summative material defeated the Feynman Effect. Ken Fountain PS See also JCE, 1994,71,938 and, most recently, ibid. 1997,74, 354. > I do use the JCE HPLC simulator and after students determine the > optimum > conditions for separation of a mixture I have them test it on a real > HPLC to see how the simulation fits the real world. They can then > look > for some of the factors that make the simulation different from real > life. > > Thank you for pointing out that paper Brian, it was very interesting. > > One fear that I have with the use of simulations is that people will > use > simulations for each individual case and never discover general laws. > An example would have been if they had modeled gas molecules in a > statistical mechanics way, they would have just kept using the model > for > different cases and never would have come up with PV=nRT. While this > equation is not exact for real gasses, it sure is handy for a first > approximation. > > -- > Michael Chejlava > Department of Chemistry & Environmental Science > Lake Superior State University > Sault Sainte Marie, MI -------------------------------- ------------------------------ Date: Tue, 22 Jul 1997 07:40:45 +0100 From: Hugh Cartwright Subject: Re: Paper 9: HMC Authority of Simulations Sylvia Eslorson writes: > The authority of the simulation and the limits of the model concern me > here, and I find within Paper 6 an intriguing opportunity for learning > about consequences of the particulate nature of matter in motion as > presented in Figures 5 and 11 of Paper 6. > You may recall: > Fig. 5. Simulation of the movement of gas phase argon > atoms above a solid surface. > As an example of such a simulation, Fig 5 shows the > establishment of a concentration gradient for argon > atoms above a solid surface under the influence of (very > strong!) gravity. collisions are elastic, and that > energy is a function of vertical position. > Fig 11. A display of a cold gas about to condense to > a liquid; pairs of molecules have already begun to form > [8]. > This is where I find the teachable moment, because in order for the student > to accept the authority of the simulation, the student wants to know how > strong that (very strong) gravity must be (fig 5), ........ AND- if the > experiment would work better if the gas were cold (fig 11). > So in a way the student wants to re-write the experiment to see if > simulation Fig. 5 was set up to take temperature into account and > conversely if Fig. 11 was set up to take gravity into account. If the > student discovers that these experiments are independent of gravity or > temperature, respectively, or that the effect is small, I count that as > learning. That is exactly the way the simulations work. In both, temperature is selectable by the user; this determines the average KE of the molecules through a Boltzmann distribution. In both simulations the Potential Energy of the molecules is determined by their vertical distance above the bottom of the container; "gravity" can then be varied from zero upwards (or downwards). Further options exist to change the form of the intermolecular interaction potential, molecular mass, etc. It follows that, even though the argon over a graphite surface simulation is designed to illustrate adsorption, students may also discover that ... * heavy molecules travel more slowly than light * under gravity a roughly exponential vertical distribution of molecular density arises * when atoms condense into a solid, symmetric structures naturally appear, despite the fact that the force field around atoms is spherically-symmetric * structure readily develops in liquids, not just solids .. and so on. One wants to encourage students to investigate a particular physical situation - like gaseous atoms over a surface - not just tell them to study a phenomenon such as gas adsorption. By providing an open-ended simulation, in which students can vary almost every parameter, the potential exists for students to discover physical behaviour for themselves. There is, as always, a downside to this. If the simulation is very flexible, students readily become entertained, and can lose track of what they should be investigating. One might also feel that this is an argument against "impossible" simulations. I am planning a set of simulations in which the main adjustable parameter is Planck's constant (how many of us recall Mr Tomkins?). Such a simulation might turn out to be downright misleading, rather than potentially useful. We shall see! Hugh Dr Hugh Cartwright Physical and Theoretical Chemistry Laboratory Oxford University, England hugh@muriel.pcl.ox.ac.uk http://physchem.ox.ac.uk/~hmc Tel (UK) 1865 275 400 (reception) (UK) 1865 275 483 (direct) FAX (UK) 1865 275 410 ------------------------------ Date: Tue, 22 Jul 1997 08:57:00 EDT From: to2 Subject: Paper 9: Substitute for Reality? Whether or not simulations are a very good *substitute* for reality, I believe they are often an excellent *adjunct* and *supplement* to reality. Reality is just too often obscure and hard to see clearly. Harry Pence writes: > Instrument simulations are particularly interesting, since they > seem to clearly focus the arguments about using simulations instead > of the real thing. My experience is mainly with instrument (or more generally, analytical systems) simulations, which I use in my advanced analytical chemistry courses. What I find most interesting about these simulations is the way they can make the inner workings more evident and more visible that a real system and how thay can reinforce the *connections* between the reality and the textbook mathematical treatment. For example, you can pass a diffraction grating around the class for students to look at it and shine a pocket laser or a flashlight on it. I do this in my classes. You can also derive and use the various equations describing grating operation. But will students really understand the connection between the two? A simulation (easily constructed with a spreadheet program) can show *both* the geometrical/graphical operation as well as the underlying equations (reduced to "computer algrbra" format), and allow the students to vary the parameters such as the grating ruling density, wavelength, angles, etc. Even more enlightening is to bypass the classical analytical derivation and simulate the operation of the grating simply by adding up a bunch of sine waves (of the the same frequency but different phases) representing the reflections from the reflective surfaces of the grooves. This really shows clearly why gratings need so many grooves to work well. For me (and I believe most students) this is more convincing than the classical analytical derivation. For another example, consider spectral interferences in atomic absorption (e.g. background absorption) and their correction. A real instrument can not record or display the absorption spectrum (because the source is not tunable). Therefore you have to imagine the spectral interactions. A simulation can work out the behavior expected under all sorts of conditions, exhibit all the non-idealities due to "Beer's Law deviations" and signal-to-noise ratio, and display the underlying (but unobservable) spectra graphically. >>Are there some simulations that you have used that just work >>beautifully? >The most successful simulations seem to be simple ones based on a >spreadsheet program. My experience, too! All of my instrument simulations are based on spreadsheet programs (see www.wam.umd.edu/~toh). Most are pretty simple. Tom ------------------------------------------------------------------------- Tom O'Haver Professor of Analytical Chemistry University of Maryland Department of Chemistry and Biochemistry College Park, MD 20742 Maryland Collaborative for Teacher Preparation (301) 405-1831 to2@umail.umd.edu FAX: (301) 314-9121 http://www.wam.umd.edu/~toh ------------------------------ Date: Tue, 22 Jul 1997 09:09:00 EDT From: to2 Subject: Paper 9 - TOH: Using Simulations after the lab Carolyn Sweeney Judd wrote: > I think that an ideal situation would be the following order: > 1. show a video of the experiment so that the student knows what to expect > 2. the student performs the experiment in the chemistry lab > 3. the simulation is done after the lab to reinforce and build on the > recent experience of the student. I do things in this order (without the video) in my "Electronics for Chemists" course. After the student build and experiment with various circuits, I have them use interactive simulations of some of the same circuits (go to http://www.wam.umd.edu/~toh and click on ElectroSim...) These look like the schematic diagrams but operate interactively like a real circuit, responding in real time to student-controlled changes in sliders and switches and displaying voltages and currents and several points in the circuit simultaneously. Why bother? Some student say that the simulations help them to make the connection between the operation of the real circuit that they built and the schematic diagram (as would be published in a textbook or research paper) which looks so different that the physical curcuit. Perhaps it's just a matter or providing a wider variety of cognitive inputs to meet students' varying learning styles. Tom ------------------------------------------------------------------------- Tom O'Haver Professor of Analytical Chemistry University of Maryland Department of Chemistry and Biochemistry College Park, MD 20742 Maryland Collaborative for Teacher Preparation (301) 405-1831 to2@umail.umd.edu FAX: (301) 314-9121 http://www.wam.umd.edu/~toh ------------------------------ Date: Tue, 22 Jul 1997 10:01:22 -0400 From: "Harry E. Pence" Subject: Paper 9 - HEP reply to BT, video game culture Brian Tissue comments on an article by Sherry Turkle that >.... described a couple of examples where students used video game >skills to successfully perform simulations; e.g., SimLife, SimCity; >rather than by developing an understanding of the underlying principles. > Has anyone observed similar trends with chemistry simulations? This is one of the real problems when using images - a problem that art critics have been discussing for some time. At least as long ago as 1970, Richard Gregory said that pictures have a double reality. The images are objects in their own right, but at the same time we see them as the object being represented. This is the basis of Magritte's famous painting of a pipe, with the caption, " This is not a pipe!" Of course, it's a REPRESENTATION of a pipe. I often find that my students confuse the representation of reality with reality itself. This is especially true when the reality consists of atoms and molecules, that are abstract concepts for many of the students. The more realistic the simulation becomes, the easier it is for students to believe that it really is REALITY. I work very hard to prevent this misunderstanding, but if I dig deeply with my questions, I find that the confusion still exists. Is this an argument for or against the use of simulations? I would argue that since the students will experience simulations in their later careers, it is essential that we do our best to help them deal with this confusion at the earliest possible stage. Ignoring the issue is not an acceptable answer. The more difficult question is, "How realistic should simulations be?" The more realistic they become, the greater the confusion, so why not make them unrealistic enough that students will be less likely to be confused. This is a delicate balance. Can we make simulations that are realistic enough to involve the students but are not too realistic. I would rather err on the side of excess realism, and plan my teaching to confront the possible confusion. I recognize, however, that this may not be everyone's cup of tea. Cordially, Harry ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | | Professor of Chemistry PHONE: 607-436-3179 | | SUNY Oneonta OFFICE: 607-436-3193 | | Oneonta, NY 13820 FAX: 607-436-2654 | | http://snyoneab.oneonta.edu/~pencehe/ | | \\\//// | | (0 0) | |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 10:08:31 -0400 From: "Harry E. Pence" Subject: Paper 9: HEP reply to SRE-Authority of Simulations Sylvia Esjornson says >....................................simulation provides a key and >that an interactive simulation may be preferred to promote learning. In >this I believe I agree with the author of Paper 9 as well. I think Sylvia has put it very well, and she is quite right, I do agree with her comments in the balance of her e-mail. Harry ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | | Professor of Chemistry PHONE: 607-436-3179 | | SUNY Oneonta OFFICE: 607-436-3193 | | Oneonta, NY 13820 FAX: 607-436-2654 | | http://snyoneab.oneonta.edu/~pencehe/ | | \\\//// | | (0 0) | |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 10:23:44 -0400 From: "Harry E. Pence" Subject: Paper 9: Hep reply to HMC Authority of Simulations Hugh Cartwright reminds me of a situation that I encountered when teaching kinetics. I had told my students several times that when molecules collide, most of the collisions don't produce the reaction. I showed a simple animation (from the program, Organic Reaction Mechanisms), and following the class I stopped one of my better students to ask how he liked the visualization. He said that he found it to be very helpful. I asked what he had learned from watching the simulation, and he replied, "Most of the collisions don't accomplish much, do they?" At first I thought that he was pulling my leg, but as I looked in his face I realized that he was dead serious. Even though I had given him the information several times, and I'm sure that he would have answered correctly on an exam, it wasn't real until he had actually seen it. This is both the power and the danger of using simulations and other imagery. This relates to Ken Fountain's comment that >This passage describes the "Feynman Effect" which I also discuss in >J.Chem. Ed. 1996,73,116 "Computational Chemistry in the First Organic >Chemistry Course" We seemed to show in that paper that proper use of >formative and summative material defeated the Feynman Effect. I believe that developing the appropriate support material and presentation format is crucial to using simulations. I'm delighted with the references that Ken provided, and I'm currently digging through my stack of JCEs to find his article. If I understand him correctly, he's dealing with a key issue in the use of simulations. Cordially, Harry ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | | Professor of Chemistry PHONE: 607-436-3179 | | SUNY Oneonta OFFICE: 607-436-3193 | | Oneonta, NY 13820 FAX: 607-436-2654 | | http://snyoneab.oneonta.edu/~pencehe/ | | \\\//// | | (0 0) | |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 10:47:23 -0400 From: reeves Subject: Re: Paper 9 - HEP reply to BT, video game culture Harry et al. >.... described a couple of examples where students used video game >>skills to successfully perform simulations; e.g., SimLife, SimCity; >>rather than by developing an understanding of the underlying principles. >> Has anyone observed similar trends with chemistry simulations? > >This is one of the real problems when using images - a problem that art >critics have been discussing for some time. At least as long ago >as 1970, Richard Gregory said that pictures have a double reality. The >images are objects in their own right, but at the same time we see them as >the object being represented. This is the basis of Magritte's famous >painting of a pipe, with the caption, " This is not a pipe!" Of course, >it's a REPRESENTATION of a pipe. I have just completed work on a commercial simulation product which I will not name so this doesn't smack of commercialism. What I will do is share some insights gained from the extensive class testing of the product, as well as by reviewer's comments. In Introductory chemistry, few students are interested in playing simulation games, even when the simulation is fun and educationally positive; free form manipulation of parameters isn't very effective if the student doesn't know where to start or what to look for. It's easy to see why such a simulation might take on the "video game" mindset for the student. We've found that most students respond much better when they are guided through the simulation by a teacher who provides step by step instructions (lessons) for the student to carry out. It's important to remember that a student new to chemistry is generally very far from "knowing what to look for" on their own, even in the best simulation. Simulations without guidence (open ended simulations) may work well for upper division students, but I question their usefulness in my general chemistry class. >The more difficult question is, "How realistic should simulations be?" >The more realistic they become, the greater the confusion, so why not make >them unrealistic enough that students will be less likely to be confused. >This is a delicate balance. Can we make simulations that are realistic >enough to involve the students but are not too realistic. I would rather >err on the side of excess realism, and plan my teaching to confront the >possible confusion. I recognize, however, that this may not be everyone's >cup of tea. Simulations can be intentionally designed to that they don't look too much like the real thing. We have a simulation where, to ensure that all the heat from a methane flame goes into the water bath its heating, the flame is "immersed" completely in the bottle containing the water. We point out in the lesson that this is impossible in the lab (real life) but we get to do it becasue we're using a simulation. This reinforces the point that what they're seeing isn't real, but a fantacy based on some basic ideas designed to help them understand those ideas. Likewise, we stay away from using actual chemical glassware (flasks, burrettes, etc), and use generic containers (bottles and big bottles) instead. Jimmy Reeves **************************************************************************** Jimmy Reeves, Associate Professor Department of Chemistry University of North Carolina at Wilmington 601 S. College Rd. Wilmington, NC 28403 910-962-3456 voice 910-962-3013 fax WWW Site: http:\\cte.uncwil.edu e-mail: reeves@uncwil.edu ------------------------------ Date: Tue, 22 Jul 1997 10:57:05 -0400 From: Michael Chejlava Subject: Paper 9 - MJC reply to HEP Jimmy Reeves wrote: >Simulations without guidence (open ended simulations) may work >well for upper division students, but I question their usefulness in my >general chemistry class. This leads to a troubling question. When do we let go of the bike seat? During my time in teaching I have seen a trend toward the teacher doing more and more for the students. Before simulations, videos, letures etc., we must tell them what to look for and what they are to learn. I thought that the goal of a college education was to produce independent learners, yet I see seniors starting research constantly looking for someone to tell them what to do. Has this reached the graduate school level yet? When can we expect them to see without having to be told where to look and what to look for? I know that they will stumble some and even fall sometimes, but we can still be there to catch them and fix their boo-boos when they do. One problem is their terrible fear of failing. How do we let them know that it is OK to be wrong as long as they learn from it. I find this whole issue very disturbing. Does anyone out there have any answers? -- Michael Chejlava Department of Chemistry & Environmental Science Lake Superior State University Sault Sainte Marie, MI ------------------------------ Date: Tue, 22 Jul 1997 10:55:31 -0400 From: "Harry E. Pence" Subject: Paper 9 - HEP reply to DR: Reality and Simulations of Reality Don Rosenthal lists a number of different situations and asks which one I would classify as a simulation. (In the interests of minimizing band width, I won't repeat them unless a specific question arises.) If I understand Don correctly, each of the situations could be based on an algorithm that either performs appropriate calculations or else makes some selection of pre-recorded data, and then displays the results to the user. If that's true, I would have no trouble calling them all simulations. My problem is the first case that Don lists, where the gas is actually in the spectrophotomer and an attached computer does calculations on the output to produce information. Is this truly reality? Most of Don's situations focus on the gray area where the simulation is further and further removed from the original data, but there is also a grey area on the other end that we normally ignore. When we look a the output of an FT-IR spectrophotometer, is this really looking at reality? We can't physically see the infrared beam or the molecules, and without a computer the output cannot be directly interpreted by our normal senses. We use a variety of methods to extend our physical senses to regions beyond what they can normally evaluate. As the link between the physical world and the data that we observe becomes more and more tenuous, do we finally come to a place where we can no longer really say that we are dealing with reality? I'm reminded of Plato's idols of the cave. Are we reaching the place where we are only seeing the shadows of the statues that are themselves representions reality? Sorry to become philosophical; I'll try not to let it happen again. ;-) Cordially, Harry ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | | Professor of Chemistry PHONE: 607-436-3179 | | SUNY Oneonta OFFICE: 607-436-3193 | | Oneonta, NY 13820 FAX: 607-436-2654 | | http://snyoneab.oneonta.edu/~pencehe/ | | \\\//// | | (0 0) | |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 11:03:35 -0400 From: "Harry E. Pence" Subject: Paper 9 -HEP reply to DR-II: Reality and Simulations of Reality Don Rosenthal also asks >Random walk simulations have sometimes been used in the modeling of >physical and chemical processes. ^^^^^^^^ >How would you distinguish between a model and a simulation? In my mind, a model is a set of assumptions that are used to design a representation of some portion of the real world. A simulation is, thus, a type of model where the assumptions are in the form of mathematical or logical statements. When a scientific theory is being developed, the set of assumptions may not be in a form that can be simply represented by mathematical or logical statements, and so it would appear to me that all simulations are models, but not all models are simulations. Cordially, Harry ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | | Professor of Chemistry PHONE: 607-436-3179 | | SUNY Oneonta OFFICE: 607-436-3193 | | Oneonta, NY 13820 FAX: 607-436-2654 | | http://snyoneab.oneonta.edu/~pencehe/ | | \\\//// | | (0 0) | |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 16:15:03 +0100 From: Hugh Cartwright Subject: Re: Paper 9 - HEP reply to BT, video game culture Jimmy Reeves writes: > In Introductory chemistry, few students > are interested in playing simulation games, even when the simulation is fun > and educationally positive; free form manipulation of parameters isn't > very effective if the student doesn't know where to start or what to look > for. It's easy to see why such a simulation might take on the "video game" > mindset for the student. We've found that most students respond much > better when they are guided through the simulation by a teacher who > provides step by step instructions (lessons) for the student to carry out. > It's important to remember that a student new to chemistry is generally > very far from "knowing what to look for" on their own, even in the best > simulation. Simulations without guidence (open ended simulations) may work > well for upper division students, but I question their usefulness in my > general chemistry class. This is exactly the conclusion reached by the developers of XYzet, the 1st year physics simulation from Kiel in Germany. A certain minimum knowledge of the underlying science seems to be necessary if a free-form simulation is to be really effective. When this knowldge is absent, guidance from the instructor seems to be vital if the students are not to waste their time. Hugh Dr Hugh Cartwright Physical and Theoretical Chemistry Laboratory Oxford University, England hugh@muriel.pcl.ox.ac.uk http://physchem.ox.ac.uk/~hmc Tel (UK) 1865 275 400 (reception) (UK) 1865 275 483 (direct) FAX (UK) 1865 275 410 ------------------------------ Date: Tue, 22 Jul 1997 11:34:33 -0400 From: reeves Subject: Re: Paper 9 - MJC reply to HEP At 10:57 AM 7/22/97 -0400, you wrote: >Jimmy Reeves wrote: > >>Simulations without guidence (open ended simulations) may work >>well for upper division students, but I question their usefulness in my >>general chemistry class. > >This leads to a troubling question. > >When do we let go of the bike seat? > In my opinion, you don't "let go of the bike seat" the first time your child rides her first two wheeler. General chemistry class is the first real exposure that most of my students have to what chemistry is really supposed to be about. What previous courses they've had generally didn't emphasize or illustrate the molecular nature of matter, and student success often had more to do with calculator proficiency than scientific insight. A simulation that guides students through key ideas, and then allows them to try other senarios on their own after they have some idea what to look for is far better for these students, in my experience. **************************************************************************** Jimmy Reeves, Associate Professor Department of Chemistry University of North Carolina at Wilmington 601 S. College Rd. Wilmington, NC 28403 910-962-3456 voice 910-962-3013 fax WWW Site: http:\\cte.uncwil.edu e-mail: reeves@uncwil.edu ------------------------------ Date: Tue, 22 Jul 1997 11:34:42 -0400 From: "Harry E. Pence" Subject: Paper 9 - HEP reply to MJC reply to HEP Michael Chejlava asks >During my time in teaching I have seen a trend toward the teacher doing >more and more for the students. Before simulations, videos, letures >etc., we must tell them what to look for and what they are to learn. It is, indeed, true that when using visual materials we must tell students what to look for and what to learn. The pedagogy of images is much more difficult than the pedagogy of text. Mental processing of an image is a very complicated process, which depends upon having the mental framework to make the image something that we can use for thinking. Most images are of familiar objects, so there is already a reference base in our minds that can be used to understand what we are seeing. When we see an image of something new, it either has to be related to something we already know or else the new framework has to be created. Every time I use an image in class, I try to tell my students what it represents. We've all seen optical illusions that play upon the inability of the mind to process images with total efficiency. The Canadian flag is an example. Is it a maple leaf, which most people see, or is it two profiles glaring at each other. Michael then goes on to say >I thought that the goal of a college education was to produce >independent learners, yet I see seniors starting research constantly >looking for someone to tell them what to do. Has this reached the >graduate school level yet? In his second comment, I believe that Mike is raising an issue that I refer to as validation. Many college students require the professor to confirm a statement before they will believe that it's true. That is, they are not capable of self-validation. They don't have enough confidence in themselves to believe answers that they arrive at themselves unless someone in authority has told them it's OK. I see this as a different issue from the need to teach by developing mental frameworks for viewing images. It's very difficult for anyone to create a new mental framework without help. On the other hand, one of the goals of instruction should be to help students become self-validating learners. One of the reasons that I use cooperative learning is that it forces students to not only develop the answers to questions on their own, but it gives the students the opportunity to test their understanding in an environment that is much more conducive to learning than the typical exam. I think that this is far more likely to make them the independent thinkers that both Mike and I are aiming for. The failure to produce truly independent thinkers has probably been around at least as long as science has existed. For example, read the story of N-rays. One famous French scientist deluded himself into seeing something that didn't exist, and soon many of his colleagues claimed that they, too, could see these rays. We teachers do our best, but we can't change human nature. Cordially, Harry ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | | Professor of Chemistry PHONE: 607-436-3179 | | SUNY Oneonta OFFICE: 607-436-3193 | | Oneonta, NY 13820 FAX: 607-436-2654 | | http://snyoneab.oneonta.edu/~pencehe/ | | \\\//// | | (0 0) | |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 11:45:52 -0400 From: "Harry E. Pence" Subject: Paper 9 - HEP reply to JR, video game culture I'm delighted to see Jimmy Reeves' comments on his experience developing simulations, especially the case where the representation in the simulation is clear but cannot really exist (i.e. having the flame inside the solution). I believe that attaining the "right" degree of reality in simulations is vital, and this is a way that I hadn't thought of to make the simulation realistic, but not confusing. Jimmy also says >A simulation that guides students through key ideas, and then allows them >to try other senarios on their own after they have some idea what to look >for is far better for these students, in my experience. I fully agree. Cordially, Harry ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | | Professor of Chemistry PHONE: 607-436-3179 | | SUNY Oneonta OFFICE: 607-436-3193 | | Oneonta, NY 13820 FAX: 607-436-2654 | | http://snyoneab.oneonta.edu/~pencehe/ | | \\\//// | | (0 0) | |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 12:51:09 -0700 From: "K.R.Fountain" Subject: Re: Paper 9: Hep reply to HMC Authority of Simulations Hurray Harry! Good for you Ken F. PS See my reply to your other message on the re-representation problem. > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | > | Professor of Chemistry PHONE: 607-436-3179 | > | SUNY Oneonta OFFICE: 607-436-3193 | > | Oneonta, NY 13820 FAX: 607-436-2654 | > | http://snyoneab.oneonta.edu/~pencehe/ | > | \\\//// | > | (0 0) | > |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 14:38:44 -0400 From: scott donnelly Subject: Paper 9 - sjd reply to MJC Michael Chejlava comments that " [d]uring my time in teaching I have seen a trend toward the teacher doing more and more for the students. Before simulations, videos, letures etc., we must tell them what to look for and what they are to learn." He continues by asking "[h]ow do we let them know that it is OK to be wrong as long as they learn from it?" I would like to respond to the quotes above. In my brief teaching career I have found that a large majority of students have the idea that science and scientific thinking is digital. That is, you either have the correct (right) answer or you're dead wrong. This way of thinking is perpetuated by the use of multiple choice testing techniques, which do not test thinking ability but rather test a knowledge base. Commonly in multiple choice exams there are four or more possible answers from which to choose but guess what? Only one is correct. It's like "correcting" a child for coloring outside the lines. What's wrong with coloring outside the lines? This right vs. wrong is played over and over again to students in their science classes and many come to believe that doing science is just like flipping an electrical switch. Rather, science is the search for pattern and predictability. Leave it to the theologians and mathematicians to find truth, i.e. right versus wrong. So with overuse of multiple choice testing students are taught that it is more important to get the correct answer to the question than to learn something about the question. And why shouldn't they think this way since their final grade depends on how many correct answers they get on the exams, quizzes, etc. As part of my statistics lab I have students measure the height of various lightposts and trees around campus. Students measure the heights using an inclinamator which they have to build themselves....without directions! I simply tell them what lightposts and trees to measure, give a brief lecture on basic trig functions, and then walk outside. On the table at the front of the room I have the necessary materials to build an inclinamator- protractor, tape, string, cardboard cylinder, and washers (used for weights). Eventually they put it together and begin measuring. Some do it faster than others. Some get it "wrong" the first time but revamp their design. What did they learn in spite of their failures? How to build an inclinamator from simple supplies and how to measure the height of objects using trig. Which student measured the "correct" height of the tree? Likely none of them but most are very close. Whether they got the correct height is not as important as how close they were to the correct height. Measurement always has uncertainty. The individual datum is written on the board and we go about doing some statistics. I do something similar with students having to find specific heat capacities of various unknown metals and/or alloys. I give very little direction and the necessary materials to do it. Although I have not had students evaluate these labs I can tell that they get some positive learning experience out of it in spite of failures and hangups. Scott D. ???????????????????????????????????????????????????????????????????????????? Scott Donnelly Professor of Chemistry Arizona Western College 9500 South Avenue 8E Yuma, AZ 85366-0929 email: aw_donnelly@awc.cc.az.us phone: 520 344 7590 "What's more important- the curvature of the graph or its color? It's a no-brainer." -Economist unknown ------------------------------ Date: Tue, 22 Jul 1997 13:31:26 -0500 From: sc18 Subject: Re: Paper 9 - HEP reply to BT, video game culture Hi Harry and all, What Harry is decribing is known to some in educational circles as the re-representation problem. It is related (in MHO) to what Reif pointed to a number of years ago in describing expert beahvior vs neophyte behavior in chemistry and physics. Part of what Polanyi calls "the masters art" is the tacit knowedge that we mobilize and bring to problem solving to obtain a focal awareness of what it is that makes the question we are trying to answer a problem. Recognition of this problematic feature of problems is what students often lack, and we do also. What we do is to re-represent the problem, spending sufficient intellectual investment until we see what makes the question a problem. The answer is then usually a matter of coherence, integration, evaluation, and creation of new knowledge in terms of what we actually bring to the problem solving situation. What I call prevenient knowledge is just that collection of tacit skills and tacit knowledge that we choose to focus on the problem. When we present our answers to the students we are focally aware of the content of our knowledge, but cannot (because we are focally aware) simultaneously be aware of the tacit knowledge we mobilized to recognise the problem. When students learn meaningfully they are able to mobilize their tacit skills and knowledge into prevenient knowledge, which they then use to re-represent the question so as to see what the real problem is. When students learn by rote, they employ all of the tacit knowledge, mobilized for them into the algorithm. Our goal is in Polanyi's words "to allow students to indwelt the teacher's art". When we use simulations we need to be sure they are not merely symbolic algorithms, but use them as another avenue to allow art indwelling. ------------------------------ Date: Tue, 22 Jul 1997 15:49:46 -0400 From: "Harry E. Pence" Subject: Paper 9 - HEP reply to KF (sc18) Ken Fountain says (in part) > What Harry is decribing is known to some in educational circles as >the re-representation problem. It is related (in MHO) to what Reif >pointed to a number of years ago in describing expert beahvior vs >neophyte behavior in chemistry and physics. Part of what Polanyi calls >"the masters art" is the tacit knowedge that we mobilize and bring to >problem solving to obtain a focal awareness of what it is that makes the >question we are trying to answer a problem. This reminds me of the first time an ed psych prof "helped" me to understand my teaching. He suggested that I work any problem of my choice as he watched. I chose a simple gas law problem and wrote down PV=nRT. He stopped me and asked, "Why did you write that down?" I replied, rather logically I thought, that this was the way to start working the problem. He asked, "How did you know to write that down? That's really the beginning of the problem!" After a very frustrating half-hour, I finally realized that I was checking off a simple matrix of the variables, and the status of the various variables told me what equation to use. He then asked, "Do you tell the students to work the problem that way?" I replied that until about two minutes ago, I didn't KNOW that was the way I worked the problem. Ever since then my approach to problem solving has changed. My first step is to try to understand how I ACTUALLY work the problem. Then, if it looks like the method is useful, I try to tell my students what I'm doing. Thanks to Ken for reminding me that experts bring a lot of mental baggage to any scientific problem, including simulations. Cordially, Harry ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | Harry E. Pence INTERNET: PENCEHE@ONEONTA.EDU | | Professor of Chemistry PHONE: 607-436-3179 | | SUNY Oneonta OFFICE: 607-436-3193 | | Oneonta, NY 13820 FAX: 607-436-2654 | | http://snyoneab.oneonta.edu/~pencehe/ | | \\\//// | | (0 0) | |_______________OOO__(oo)__OOO____________________________| ------------------------------ Date: Tue, 22 Jul 1997 18:20:24 -0400 From: scott donnelly Subject: Paper 9- sjd reponse to HEP Harry Pence writes about his learning experience with a ed psych professor and how "[a]fter a very frustrating half-hour, I finally realized that I was checking off a simple matrix of the variables, and the status of the various variables told me what equation to use." I've had similar experiences myself with the physics prof here. He is trained in theoretical cosmology. You know, here's the experimental observation now what variables constitute a reasonable explanation for the phenomenon. I would like to describe an activity I do relating to gas laws. This activity, which involves variables in the ideal gas equation, is done as a conceptual exercise during lab recitation. It is important to note that students have not yet been lectured on gas laws or the definitions of pressure and temperature. Students are given a conceptual problem where they are to rank from greatest to least the likelihood of explosion for various cylinders of a gas. The cylinders have the same # of molecules of gas. But the temperatures and volumes of the cylinders may either be the same or different relative to one another. There are 6 cylinders in all. Students must also explain why they ranked the cylinders as they did. Students list their ranking on the board and then must find another who has a different ranking. Each student must try to convince the other that their ranking is incorrect. I then ask for volunteers to go to the board to duke it out. There is usually no shortage of volunteers for this. The audience can also participate in the debate which I may add is oftentimes lively. The answer is finally written on the board but this sometimes is not enough to convince some. What's the whole point of the activity? Students are asked to solve problems without resorting to equations. Yes, some students remember the ideal gas law from high school. Even so the instructor could stipulate that under the said conditions the gas deviates significantly from ideality. But for most students the ideal gas law is not known or they don't recognize that it can be applied to the problem assuming ideality even exists. What is avoided is what Harry describes as "...checking off a simple matrix of the variables,..." This same activity can be used for conceptually determining the internal energy of a gas at various pressures, temps, and # of molecules present, for conceptually determining the temp of an ideal gas at various pressures, # of molecules, and volumes, for conceptually determining the temp of an ideal gas with various amounts of internal energy, volume, and # of molecules, and for conceptually determining the maximum temp change of water when a block of metal at varying temps and mass is added to the cup of water. The activity introduces students to simultaneous multi-variable thinking. The fact that a cylinder can explode is within students' personal experiences. This adds applicability and usefulness to the activity. Scott D. Scott Donnelly Professor of Chemistry Arizona Western College 9500 South Avenue 8E Yuma, AZ 85366-0929 email: aw_donnelly@awc.cc.az.us phone: 520 344 7590 "What's more important- the curvature of the graph or its color? It's a no-brainer." -Economist unknown ------------------------------ Date: Wed, 23 Jul 1997 07:57:51 +0100 From: Hugh Cartwright Subject: Re: Paper 9- hmc reponse to SD scott donnelly writes: > I would like to describe an activity I do relating to gas laws. > .... students have not yet been lectured on gas laws or the definitions of > pressure and temperature. Students are given a conceptual problem where they > are to rank from greatest to least the likelihood of explosion for various > cylinders of a gas. ............ Students > must also explain why they ranked the cylinders as they did. This is an interesting exercise, and I'd like to hear more from Scott about the explanations given by students for their ranking. I can understand them arguing that small cylinders are more likely to explode; after all most students will have tried to squash gas molecules in a balloon into a smaller volume, and found an "explosion" often results. Although temperature is trickier, I expect most students correctly guess that high temperature increases the likelihood of explosion. Students may have seen on television film of compressed gas cylinders exploding in a fire. But where do you go from here, Scott? Do some students then conclude that "things are less stable at high temperature"? And if so, is there some way in which your procedure gets around this difficulty? (Or maybe it's not a difficulty, though it seems to me to be a potential source of confusion.) Hugh Dr Hugh Cartwright Physical and Theoretical Chemistry Laboratory Oxford University, England hugh@muriel.pcl.ox.ac.uk http://physchem.ox.ac.uk/~hmc Tel (UK) 1865 275 400 (reception) (UK) 1865 275 483 (direct) FAX (UK) 1865 275 410 ------------------------------ Date: Thu, 24 Jul 1997 15:26:21 -0400 From: scott donnelly Subject: Re: Paper 9- sjd response to HMC MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Greetings All !! Previously I wrote about a gas law activity where students had to rank from greatest to least the likelihood of explosion of 6 different cylinders of a gas under various conditions of temp and volume. For this example each cylinder had the same # of gas molecules. I received a number of emails asking me to discuss how students went about trying to rank (solve) the puzzle. First, the gas I choose was nitrogen. Students didn't think that nitrogen gas could explode. They confused combustion, which involves a conversion of reactants to products and subsequent energy conversion, with an explosion, an event that does not necessarily require a chemical change to occur. Second, as Hugh pointed out in a previous email, students "...argu[ed] that small cylinders are more likely to explode; after all most students will have tried to squash gas molecules in a balloon into a smaller volume, and found an "explosion" often results." Conversely, it was argued that cylinders of greater volume were less likely to explode. Although these are reasonable assumptions under certain and specific conditions, they in a particular example in this activity did not yield the correct answer; some students failed to take into account the temperature, which in one example was significantly greater in the larger volume cylinder than the smaller volume cylinder. The significant difference in temp rendered the larger volume more likely to explode than the smaller volume. But in another example the temp difference was not great enough to make the larger volume cylinder more likely to explode (cylinder 1 @ V = 2L and T = 480K and cylinder 2 @ V = 4L and T = 600K). Third, when two cylinders had the same volume but different temps, students recognized that the cylinder at higher temp had the greater likelihood of exploding. They also recognized correctly that when at the same temp but different volumes the likelihood of explosion was greater for the cylinder of smaller volume. Hugh asked- "Do some students then conclude that "things are less stable at high temperature"?" After this exercise I believe that students are less likely to conclude this since they now know that another variable is important- volume but I have no quantitative data to show this though as I did not do a pre- or post-test questionnaire. It was more of a spur of the moment activity after having talked to my physics colleague about conceptual learning. The # of molecules is also important (frequency of collision per unit area at some value of kinetic energy) but in this activity this was not the case. Gas laws lend themselves beautifully to conceptual thinking and introducing students to multi-variable analysis. There are many variations of this type of activity that can be developed. Examples include ranking the temp of an ideal gas at different P, V, and # of molecules, ranking the temp of an ideal gas with varying amounts of internal energy, V, and # of molecules, and ranking the internal energy of an ideal gas with varying # of molecules, T, and P. These gas law conceptual activities are best done before students have been lectured on gas laws as otherwise many will just resort to plugging in numbers into the ideal gas equation. As I see it the latter serves no real learning purpose nor does it encourage critical thinking or conceptual understanding. The activities can be time-consuming if intended to run the activity as I do: 1) have students try to convince their neighbor that their ranking is correct, then 2) list the rankings on the board and finally 3) debate them. I usually do this during lab recitation or as a take-home exercise to be turned in the next class lecture and then debated for the first 15 minutes of class. Cheers! Scott D. Scott Donnelly Professor of Chemistry Arizona Western College 9500 South Avenue 8E Yuma, AZ 85366-0929 email: aw_donnelly@awc.cc.az.us phone: 520 344 7590 "The excitement that students can feel in understanding the physical explanation for some phenomenon that they see or experience almost daily is one of the best motivators for building scientific literacy." -W. Thomas Griffith ------------------------------