computer m i ef
AA
edited by JOHN W.MOORE
Eastern Michigan University. Ypsilanti, MI 48197
Student Use of Computers for Solving Problems: Tools or Crutches? Richard Cornellus Lebanon Valley College, Annville, PA 17003 Daniel Cabrol and Claude Cachet Universite de Nice, 06034 Nice, France
When hand-held calculators first appeared in chemistry classrooms. their use was controversial: Should thev he nermitted duiing exams? Initially they cost several hunired dollars. m a s it fair for a student to use such an expensive electronic device as a crutch, and perhaps gain an advantage over other students? Was i t acceptable for the touch of a button to supply the value of a logarithm? These questions are no longer asked. Today students walk into chemistry exams regarding calculators as indispensable tools, and we are faced with the logical next step from the electronic revolution: portable microcomputers. The same sorts of questions that were asked about calculators may now he asked about comouters. The ereater nower of microcomouters makes the questions more challe&ing. If these questions are to disappear in a few vears as thev did for calculators. the way that chemistry is-taught must certainly change. m his article explores some of the questions and some possible answers. Advancing Technology
Hand-held calculators can rapidly carry out addition, multiplication, square roots, and exponentiation, and many of them can handle standard deviation or even linear regression as well. T o the extent that calculators are limited to these operations, few individuals now question their unrestricted use in chemistry classrooms. Except for elementary school students learning fundamental arithmetic facts, it has been eenerallv accented that calculators are valuable tools, although t11e) may serve as crutches for the computationally dssfunrtional. In che~nistrvthe underlvine . assumotion is-that a student's is not measured by hkr ability to carry out simple arithmetic ooerations. when pro&ammable calculators first became available, the situation was essentially unchanged because the student was forced to build his own program & ssitu. The student had to be able to carry out the proper sequence of operations in order t o program a calculator to do the calculations. Thus these programmahle calculators were no more crutches than calculators which could not be nroerammed. . When permanent memories and magnetic cards appeared, the use of programmable calculators did carry the danger of being a crutch. An instructor could not know whether the student using recorded programs had a real understanding of the program operations, and the same uncertainty existed about the student's understanding of the mohlem to be solved. In some cases, correct answers might demonstrate only the ability to choose the appropriate program. The calculator could then be used as a crutch rather than as a 1094
Journal of Chemical Education
- -
tool. Should this calculator and the accomoanvine collection . of programs he permitted during exams? Although important in principle. the auestion about calculators with recorded pkograms did nbt need to be answered because most programs running on these calculators were limited to specific applications and could not he expected to he directly applicable to a question on an exam. Other programs were too general and needed adaptation. Thus, the successful use of these programs would require considerable effort and understanding on the part of the student. The Impact of Software Avallablllty The question becomes more critical with the availability of portable microcomputers. The differences between microcomputers and oroarammable calculators lie not onlv in the differences in c h p u t a t i o n a l power and memory caiacitv, but also in the third-partv software sunnort that microcomputers have received. Thousands of a h h e r s market software for microcomputers, and dozens now produce microcomputer softwarefor chemical education. Microcomputers provide the opportunity for the collective wisdom of software authors around the world to support students in their homework, and portable, battery-operated units can now heln students even durine exams. The question of the appropriate use of this equipment has become more urcent. If students are nermitted unrestricted use of microcom&ters, are we changing the aims of education? When we test students, are we still assessine their scientific knowledge or instead their capability to ;se sophisticated programs? Should the technology alter what we teach and the questions we ask on exams? In part the answers to these questions depend upon the context: The answers are different for training and education than they are for examination and evaluation. Before we answer these questions, we need to explore the power of software for microcomputers. The Nature of software for Chemical Education Microcomputer software is now an acceoted and erowine member of the collection of tools used for instruition in chemistry. The different types of software may he generally divided into two categories depending upon the identity of the primary user. Some programs are designed for instructors to use in front of a class or individually with students to demonstrate chemical principles, portray a model, or simulate a process. Some programs in this category are authordriven. The author of the softwale had determined the spe-
cific topics, the sequence in which they will be covered and perhaps even the rate at which they will he covered. Such programs require little effort on the part of the instructor. Other programs are instructor-driven. These are general purpose programs which the instructor may be able to use for a variety of topics, and which are of little value to an instructor who wants the software alone to do the teaching. Amone those Dronrams desianed for the student to use independenrlvoith~instructor;both author-driven and stw dent-driven styles mav be ronsidered. An examination of the software currently available, however, reveals that nearly all programs designed for student use are author-driven. Few programs permit the student to specify the topic to be considered or to create a problem to be explored. If a program does not permit a student to define the problem, then that program is of little value as a tool (crutch?) either for homework or during anexam. Ingeneral, the programsfor student use are written to help students reach a specific educational goal. Once a student reaches this goal, the programs lose their value except for occasional review. General-Purpose Software General-purpose software is by its very nature user-driven, and has the potential to be very powerful in students' hands. Word-processing programs could hold hundreds of pages of paraphrased passages from textbooks and support keyword searching. Alternatively, data-base management programs could help organize and sort the same information. Clearly such programs could help students in their work. No objections are likely to be raised against their use a t home, in the library, in independent work in the laboratory, or in any other aspect of student training, hut should their use he permitted during exams? For an answer to the question we may make a comparison with an open book examination. In such an examination, an instructor would not ask a student simply to provide information contained on the pages of available hooks. The same consideration applies for the use of computers in general and of data-base management programs in particular. If the goals of an instructional unit include acquisition of factual knowledge, then the exam should be designed in such a way that the achieqement of these goals will he effectively tested, and the use of notes, hooks, computers, or other memory crutches would not he appropriate. Once the chemical facts for a given topic are mastered, higher educational goals may be pursued. These include the organization of information, critical evaluation, analyzing data, looking for correlations, and the selection of appropriate information to answer specific questions or problems. As the amount of chemical information needed to develop such learning activities increases, the need for some form of data storage becomes apparent. Then books, cardboard files, or data management software may he used as tools rather than as crutches. The styles of general purpose software mentioned so far can he labeled as "passive," in the sense that all the operations to be performed on the data hase (organizing the file, entering data, searching, etc.) must he initiated by specific commands from the user. General purpose software can also play a more "active" role, performing tasks which are not explicitlv expressed in the form of commands and which may noteven he understood by the user. Templates for general spreadsheet programs could he filled with mathematical formulas for prohlems, complete with annotations about each variable and the kinds of problems for which each formula could he used. These programs could then be used to provide explanations of formulas and at the same time serve as automatic calculators. Althoueh the cumputariunal power or rhrir prngrams is limited, they can hnndle a sururiiinrlv laree number of different kinds ut' problems. scientific spiead:heets such as TK! Solver1 are capable of solving most mathematically based problems
found in undergraduate chemistry if the proper data and equations are entered. TK! Solver gives numerical solutions to the stated problem. Other mathematical packages such as muMATHImuSIMP2 are capable of symbolic manipulations3 that can yield general solutions to problems. If we consider learning the mathematical operationsand manipulations that these programs perform as fundamental to chemical education, theu the use of such Droerams can cerlaid? be considered as crutrhes. ~ o d a ~ ' r n instructors &~ \r80uldsay that learning the mathematical operations should y ago, indeed be a part of chemical education. ~ o t m a n years however, many would have also included logarithms. Technology has changed what we teach and will likely introduce changes more profound than those begun by the pocket calculator. We need to evaluate critically our educational objectives in the perspective of the electronic world in which we live. Although general-purpose programs are powerful, each would require considerable effort on the part of a student before it would he a useful tool for chemistry problems in general. If a student were to go through the effort necessary to prepare these programs for use, the result would he a collection of tools which would be valuable for the student to use and which would be in major part a product of her own creation. Dedicated Software In order to find a aowerfulnroeram which would he -imme~ ~ ~ - - - diately useful for c'hemistristidents we must look to the publishers of software for chemical education. The format of most software for chemical education is that of asking stndents questions rather than providing solutions to problems. Such programs cannot answer student's questions, except in very limited cases. One new program that the authors of this article have written, however, provides solutions to prohlems that students provide. The program is called G e ~ r g e , ~ and its initial version handles problems involving the fundamental quantities volume, mass, and number of moles (or number of particles), as well as other quantities derived from these fundamental ones. As a sample of the manner in which Georee operates. consider a ouestion reeardine a solution of aniline. If a student wanted to find the kolar concentration of aniline, she could provide the program with the volume of solution, the volume of aniline used, the density of aniline, and the chemical formula of aniline. George could find the molar mass of aniline from its formula and theu use dimensional analysis to find the answer. The program can also find the solution to a more complex problem such as "What volume of 1.0 M hydrochloric acid would react with exactly 10.0 g of chalk?"5For this problem the studeut must provide relations between quantities to identify chalk as calcium carbonate and to define the stoichiometry of the reaction. Like a good student, George shows his work, explaining which quantities are multiplied or divided by which others and drawing a diagram or uetworkQo show how all of the data and the relations have been used tonether (see fieure). George was designed to help students understani how problems are solved, hut the program is also a capable solver of problems for introductory chemistry. ~ u r e l ; other student tools/crutches will soon appear. If a student can type ~
~
~
~~
~
~
' TKI Solver, Software A m , Wellesley, MA, 1983.
muMATHlmuSIMP-80 Symbolic Mathematics System by Software Warehouse. distributed bv Microsoft. Bellevue. WA. 1981. An introduction of the use of symbol-ianfpulatfngIangJages and EDUC.. 61. 629 (1984). programs is provoded oy Raioy. T. E.. C ~ E M Cornelius, R.. Cabro.. D.. an0 Cachet, C.. George, COMPress. Wentworth, NH, 1985. Johnstone. A. ti., J. CHEM. EDUC..61, 847 (1984). Enuc.. Ashmore. A. D., Frazer, M. J.. and Casey, R. J., J. CHEM. 56,377 (1979).
.
Volume 62
Number 12 December 1985
1095
Network ............................................................................................................................................ Here is a diagram of hou 1-used the various pieces o f znformatlon to reach a solution.
For details ty e the relevant letter or number. ESC &splays menu. Diagram from the program George showmg how the def ned problem are camomeo lo reach the answer.
aam
from a studem-
data into a program and see the entire solution within a few seconds, is the program a crutch which students should be forbidden to use, or is it a tool which can extend the student's capacity to learn complex chemistry prohlems? The answer appears to be yes, it is a crutch or a tool, depending upon how, when, and where it is used. The same program could be a tool when used for homework and yet serve as a crutch if the student did not know how to work prohlems on an exam without it. Conclusion Calculators are now widely regarded as important tools rather than crutches by chemical educators, but they are certainly not regarded in the same light by those teaching elementary school students learning arithmetic facts. The ~ r i m a r vdifferences are the educational level of the students and the extent to which the students understand the nature of the calculativn [hat the device is performing. The use of computers should be judged in the samecontext. If achemistry student is learning how mass, volume, and density are related, then reliance upon a computer program to carry out the mathematical manipulation and calculations may impede the student's understanding of the manipulations. Once the student has a thorough understanding of the process. such a nroeram mav serve to relieve the student from thediudger;of tedious calculations and permit that student to focus o n ~ r o h l e mof s a e a t e r mathematical (and chemical) complexity. Formula weiehts an example of how computers - provide . may serve as crutches or as tools. ~ e & i n l y a student should
1096
Journal of Chemical Education
be able to find the formula weight of a simple compound without the aid of a computer program. Once a student understands how to work with-foimulas as complex as Ca(OH)&H20, however, little is to he gained by having him or her work with more complex formulas. Then a program which can find formula weights from the formulas becomes a useful tool. If computers are used in exams, then the exams should not attemnt to determine the abilitv of the student to obtain a simple result, hut instead should try to measure how well a student can organize knowledge, apply principles, and evaluate results. In practice, we can expect that most instructors will very slowfi modify the way they assess the students' capabilities. Unless an instructor has taken an active part in the introduction of the use of computers, his or her reaction may be a total ban on computers during exam sessions. This is an unfortunate solution because i t discouraees the use of tools " which can make students more productive. As the evolution of electronic technolow -" and software for education continues we may see a mixture of attitudes. Just as we now see hoth open-hook and closed-hook exams, we may see hoth open-computer and closed-computer exams. Each instructor will keep his or her freedom, and depending upon context, will define educational objectives (explicity or implicitly) that will or will not allow computers. Today few instructors pay anyattention to how a student obtains a logarithm. Despite the actions of any individual instructor, the teaching of chemistry will slowly move so that computers may he used anywhere by students. We may see in the near future new software tools. such as "hare en~ines" for expert systems working on data bases, with which students may build their own system for solvina problems. Then these systems will be thk products of individual students and mav be the common~lacetools of tomorrow. The feasibility of creating such software for a popular microcomputer has already been d e m ~ n s t r a t e d . ~ We can expect that students will increasingly rely upon computers to carry out calculations and solve prohlems. We should view this development as healthy. We must accept the students' dependence upon machines just as surely as we accept our dependence upon computers to generate the Fourier transform of a free induction decay to produce an NMR mectrum in the freouencv domain. If we wish to continue to push the frontiers of science, we must take advantaee of tools which will let individuals accomnlish more. We luzl he teaching fewer calculations as computers become more powerful and more commonplace. The sooner we recognize and accept this progress, the sooner we can help our students reach higher educational goals.
' Cabrol, D., AUTODIDACTE. Universitb de Nice, work in progress.
