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Another Issue, Another Challenge
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John W. Moore
University of Wisconsin-Madison, Madison, WI 53706-1396 |
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This issue is out of print. |
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Life certainly is interesting. This issue of JCE: Software contains a number of firsts. It is the first issue to contain an update of a previously published program (two, in fact); it is the first issue to include a brief note (akin to Bits and Pieces in the Computer Series in J. Chem. Educ.); it is the first to include an artificial-intelligence program or expert system; and it is the first to involve a program that in its compiled form was larger than the disk we distribute it on. All of these things have kept us on our toes--and for longer than we anticipated. We apologize for the lateness with which this issue is reaching you. The computer medium differs from the written word in that programs and data can be updated and the updates incorporated directly into the previous version. Consequently we shall from time to time publish corrigenda in electronic form. The first of these are in this issue and they affect KC? Discoverer (1) and Spreadsheets in Physical Chemistry (2). The data file for KC? Discoverer has been updated to include, among other things, new atomic weight values for some elements, and the number of videodisc players supported by the program has been expanded from one to three. One of the spreadsheets in the physical chemistry issue has been modified so that several algebraic signs are now correct. In this case we appreciate the efforts of a user of the issue, Phillip Pavlik, Northern Michigan University, who detected the error. This issue also contains a program by Pavlik, Bravais, that constitutes a short note rather than a full publication. Though it serves a useful function in its own right by displaying the Bravais lattices in a graphic, dynamic fashion, Bravais also demonstrates the capabilities of a graphics package that programmers may wish to use. The latter is also by Pavlik and is available from Project SERAPHIM. Inclusion of notes such as this, or of more than a single program in an issue, will become the rule rather than the exception as JCE: Software continues to grow. PIRExS by James Birk, Arizona State University, is unlike any program yet published in JCE: Software, and indeed is a major programming achievement. Though organic chemistry is well enough organized that expert systems seem feasible, the same would probably not have been said about inorganic chemistry before Birk created his expert for predicting whether inorganic substances would or would not react. PIRExS could score very well on the descriptive parts of the ACS/DivCHED examination in general chemistry, and it can answer close to 100% of the questions in standard textbooks that involve predicting what will happen when a single reactant is heated or two are mixed. Furthermore, the program can tell us the rules it used to make the prediction. Birk's program has at least two very powerful implications. First, it makes it almost trivial for students to try out possible combinations of reactants to see what reactions they may undergo. This capability, which requires only entering the formulas of the reactants, is very different from a textbook, where the organization usually is by element or periodic group. Students can use PIRExS, for example, to try out reactions they may be considering as part of a several-step synthetic sequence. Or they can use the program to generate data from which their own predictive rules might be derived. The program makes playing around with reaction chemistry quick and easy, and thereby insures that students will do more of it. The second implication has to do with the extent to which we can teach general rules (rather than facts to be memorized) in general chemistry. While constructing PIRExS, Birk had to add significantly to the list of rules we normally teach for deriving oxidation numbers. (He has 15 instead of six or eight.) Moreover, the rules are more complicated than those in most textbooks. As users of the program will see, this is also true in many other areas. Instructors can customize PIRExS so that it will tell students the rules it used to make a prediction (either as simple explanations or as detailed explanations), and these explanations are not trivial in most cases. Perhaps Birk's program, in addition to its pedagogical uses, can make us more aware of the tremendous conceptual background that students actually need if they are to make even seemingly simple predictions about what will happen when substances are mixed together and allowed to react. Chemistry is not trivial to learn, though it may seem so to those of us who have already learned a lot. Finally the technical question: how can we get more on a disk than will fit? Initially we hesitated about publishing PIRExS because the program would be unusable by many subscribers. The most recent Project SERAPHIM hardware questionnaire revealed that although many of you have 3.5-in. disk drives, the majority still use 5.25-in. drives. How could we make the program usable for those who do? The answer was provided by PKware(3), a Wisconsin company that sells data- and program-compression software. Their latest product (which has not yet been announced, has no official name, was going to be ready real soon now at least two months ago, and was hard for us to get in time for this issue to be produced) will compress a compiled program file to approximately half its original size. Moreover, the PKware product generates a compressed file that is able to uncompress itself as it begins to run, recreating in memory the original executable program. We appreciate the efforts of the PKware staff, who worked directly with the Technical Editor to prepare a working copy of PIRExS in compressed form using their unannounced product, and of the Technical Editor himself, who drove part way across the state just to get the program compressed in time for publication. We hope the PKware product will soon be announced and will be as useful to many others as it has been to us. But you don't have to worry about such technical details to appreciate the software in this issue. We hope it will suit your needs even better than PKware's did ours! Literature Cited |
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Last Updated: April 26, 2001 Created: December 3, 1996 |
Created by: J. L. Holmes Comments to: jceonline@chem.wisc.edu |
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| © 1997 Division of Chemical Education, Inc., American Chemical Society. All rights reserved. | |