IV: Computers in Laboratory lnstruction Chairman: Stanley C. Bunce, Rensselaer Polytechnic Institute
Plenary Lecture: The Computer in Laboratory lnstruction Speaker: Charles L. Wilkins, University of Nebraska Over the years since electronic digital computers were introduced, the primary application of these valuable research tools in chemistry has been to perform computational tasks associated with mathematical development of theory and data analysis. As scientists have taken advantage of the speed and reliabilitv of these impressive computational &achines, computeri have becomk an essential element of modern science. In the past 30 years, enormous advances in computer technology have resulted in computational speed increases by a factor of almost 10' and reductions in comnuter weights from several tons to a few pounds. Concurrent economic developments have resulted in the readv availabilitv of these highly reliable, miniaturized, simpie-to-use computers in tLe ixperimental lahoratory as a standard adjunct to analytical instrumentation. With these advances have come excitine" new ~ossibilities for direct computer-coupled experimentation and a need to introduce to the chemistw curriculum formal instruction aimed at grounding today's chemistry students in the techniques of laboratory computing. Equally important is the use of the computer as a teaching tool itself (a technique which has come to be known as computer-assisted instruction, or CAI). Important as this latter use is, it has been covered a t length elsewhere (1, 2 ) and, accordingly, the focus of this discussion will be the question of how to train students in the use of the laboratory minicomputer as anessential analytical chemistry instrument. Laboratory Instruction in Minicomputer Use
There are a number of ways a scientist may use the computer in the laboratory. Generally, these may be grouped into several broad categories. Simple data acquisition or data reduction are obvious uses. Simulation of experimental processes and experiment control are two other potential uses. Finally, data management via comnuter storage retrieval of ex~erimentaldata is desirable. within theucontext of laboratory instruction, it is quite important to train chemistry students in the data acauisitiob and control aspects of iaboratory computing. his, in turn, necessitates a systematic approach to instruction which must include some elements of dieital electronics and hardware and software interfacing. To accomplish these ends. careful attention to the selection and design of instructioia~ minicomputer systems is necessary. Foremost considerations in the choice of a teaching computer system are its economy, ease of operation and maintenance, and the availability of suitable peripheral devices and software support (3-5). One approach is exemplified by a course developed a t the University of Nehraska-Lincoln (6). Here, modular hardware was used, including modular analog to digital and digital to analog converters, patch panel connectable digital input/output, control and sense lines (7). A modular software approach, using Realtime Basic (4, 5, a), facilitated the rapid introduction of students to the fundamental concepts of laboratory com-
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puting with a minimum delay. Where it was appropriate, support facilities of larger computers were utilized (9), hut these were not essential to the basic instructional method employed. The course proceeded from consideration of the simple elements of digital logic and Boolean algebra, using inexpensive commercially available logic components and training devices, to chemistry-orientated computer interfacing experiments. A description of the general course outline and a discussion of the results of teaching this course several times have been presented elsewhere (6). The experiments and supporting materials have been combined into a laboratory manual (8) which can provide a basis for development of similar courses, ar inclusion of such experiments in existing courses. Experiments cover a broad variety of topics beginning with simple integrated circuit applications, proceeding to consideration of data acquisition principles and techniques and finally, a number of computer-assisted chemistry experiments are included. Among these are experiments in gas liquid partition chromatography, potentiometric titration, and spectrophotometry. Conclusion
It is clear the instruction in the use of the laboratory computer as an essential analytical chemistry laboratory instrument must become a part of the laboratory instruction program in chemistry. Furthermore, it is likely to become a required part of future professional chemist's training. With the rapid proliferation of microcomputers, analytical instruments designed around such processors will soon become commonplace. This will further necessitate the familiarity of working chemists with the principles involved in synergistic computer-instrument interaction. I thank my colleagues and students who have made so many contributions to the development of the ideas presented here. In particular, I thank Dr. Charles Klopfenstein, Dr. Sam Perone, and Dr. Ray Dessy. I also thank the National Science Foundation for generous support through grant GJ-441. References il! Mstoon. J. 5.. Mark, . l r . H. B., and MscDonaid. .IF.. H . C . , IEditorsI "Compufer~ Assisted lnrfruelion i n Chemistry. Part A: Genersl Appmaeh," Msrcol-Dekker I n c . New York. 1974. 121 Mattson, d. S.. Mark. dr.. H. R.. and M a c h n s l d , Jr., H . C.. IEdilnis! "ComputerAssisted InLnrclion in Chemistry. Part B: Applica,ionr." Marcel-Dekker 1°C Ne,"Y"rk. 1974. 13) WIl*inr. C . L..and Klapfenrtein, C, E.."Proc. Second C o d on Cornputerr in the Undergraduate Curricula." Dnrtmouth College. Hanover. New Hampshire. 1971. p 269. (41 w i a b n s ,c . L., and ~ i ~ ~ C. f E.. ~ ~~ h ~m t ~ 2.561 ~~ ih (19721. ~. . (51 Wilkins. C. L.. and Klopfenscein. C. E.. Chemrerh. 1.651 llY721. I61 Wilkins, C. L.. and Williams. R. C.. "Proe. Fiith Conf. nn Cnm~urersi n the under^
Contributed Papers Computer Enhanced Learning in Chemistry Laboratory at Syracuse University
Utilizing Computers in the General Chemistry Laboratory
Leslie N. Davis and Daniel J. Macero, Syracuse
Ronald W. Collins, John W. Moore, a n d Clare T. Furse, E a s t e r n Michigan Uniuersity, Ypsilanti,
Uniuersity, Syracuse, New York Computer enhancement of laboratory experiences in two distinct types of courses has been implemented in the Chemistry Department a t Syracuse University. We shall describe a Gas Law Laboratory (designed for a chemistry for non-science majors course) which combines actual laboratory apparatus handling and data taking with a computer experience which tutors and reinforces principles while extending the laboratory experience with a comprehensive simulation of the experiment including the possibility of parameter manipulation beyond the resources of normal laboratory apparatus. We shall also describe three tutorial type programs in electronics, gas chromatography, and spectroscopy (uv, visible, ir) designed for an upperlevel course in chemical instrumentation in conjunction with a multi-media approach to laboratory work in these areas. Student reactions and contributions to the use of CAI were discussed, as well as our assessment of the future of CAI a t Syracuse University.
Time-shared Learning in General and Analytical Chemistry Laboratories
Robert J. Merrer, Western Connecticut S t a t e College, Danbury, Connecticut Subsequent to the first experiment a mini-course in Basic extending over two three-hour laboratory periods is given. A program which has been thoroughly analyzed in class, involving the first experiment, is run. Manual calculations had been performed previously. The student is required to write algorithms for selected experiments. These are graded along with the completed write-ups. Later in the semester the student is introduced to linear regression analysis. In analytical chemistry, spectrophotometric analvses follow for which a least-sauares treatment is employed. This treatment is also useful to compare instruments, monitor instrument performance on a day-today basis, and carry out error analyses. A simulation is used in connection with the pK, determination. Values determined in the laboratory are utilized as input in this simulation which involves Gran's Method. In general chemistry, programs have been written and utilized, among which is a kinetics program for the iron(II1) catalyzed decomposition of hydrogen peroxide.' Objectives of this approach are: (1) to teach the student to effectively collect, organize, and utilize experimental data; (2) to develop discipline and clarity in communication of that data; (3) to enable the student to ask and solve his own problems (within the context of the course) independent of the instructor; and (4) to expose the student early in his college career to the utility of the computer in order to solve meaningful problems. Student reaction and effects of the program on both the student and the instructor were discussed.
'Robert J. Merrer, J. CHEM. EDUC., 50,514 (1973)
Michigan Computers have been used in our general chemistry laboratory program for four different purposes: data reduction; pre-lab data simulation; intermediate statistical evaluation of data; and grading assistance. The conventional data reduction usage has been strictly in batch mode, utilizing programs. Students submit their own data and include the output with their report. In some instances such as the hydrogen peroxide-iodide ion kinetics experiment, the computer output is incomplete; i.e., the program calculates only one of the exponents in the rate equation and the student must calculate the other exponent. Computers are also used to secure intermediate checks on data where appropriate. By utilizing programs in time-shared mode, students can secure rapid statistical checks on either the precision or accuracy of their data. For example, when standardizing an acid or base the students can check the precision of their data after several titrations to determine if more trials are necessary. The computer is also used to generate pre-lab, individualized, simulated data for selected experiments. By requesting that each student perform the calculations prior to starting the experiment, a better understanding of the concepts is developed. Overall, these various computer-based techniques have served to both improve student performance on existing experiments and to allow the introduction of new quantitative experiments. Finally, computer programs for checking the results have markedly streamlined the grading procedures for the instructor.
Time-sharing Computing in a General Chemistry Laboratory
Ray R. Reeder, Elizabethtown College, Elizabethtown, Pennsylvania For the past three years, students in a general chemistry laboratory have used programs closely keyed to their experiments to check the results of manual data analysis. The interactive data analysis (IDA) programs currently in use are written in Fortran IV.. im~lemented on a DEC . System 10 computer, and are accessed by students on TeletvDe terminals near the lahoratorv. An informal dial o g u ~ f o r m a is t employed which includes program recognition of common errors, suggestions for corrections, and many student-exercised options for data correction, calculation correction, and improved least-squares fitting. Detailed cumulative records of program executions are kept to measure the effectiveness and frequency of use of various program features. The programs require 3-4 K of core and approximately 20 min of terminal time per execution. Compared with previous instructor-submitted and student-submitted batch processing, the response to these programs has been large and enthusiastic. Eighty-eight percent of the student users expressed a positive reaction to the computing experience. Seventy-six percent found the programs helpful in spotting errors and improving understanding of the data analysis, while 88% considered the optional branches valuable. Statistics on use support these opinions but indicate that for all their appeal, asVolume 52, Number I , January 1975
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signed programs were used 2-3 times as frequently as completely optional programs. As student experience grew, attention shifted from the correction of input data to more sophisticated corrections of calculated results and the selection of reliable data for least-squares fitting.
Utilization of the Minicomputer in Physical Chemistry Laboratory Instruction
Paul E. Field, Virginia Polytechnic Institute a n d S t a t e University, Blacksburg, Virginia. The computer is not only a desirable accessory in the ~bvsical chemistrv laboratory course, it is an essential ap. . paratus for proper instruction in the techniques of physiw rorhemical experimentarion and principles of physical chemistry. The philosophy of instruction in the l a b o r a t q course in physical rhemistry at Virginia Pdytechn~rInstitute and State Cniversity is based on the three ohjerti\.es: ( I ) to illustrate theoretical pr~nciples, 12) to demonstrate ex~erimentaltechniaues. and (91 to elucidate measurements methods. ~ h e s ethree objectives represent the science, the art, and the craft of the discipline, respectiveIv. Althoueh the first two obiectives have been oursued in the past, adequate instruction in measurements methods has lamed considerablv behind the utilization of them in p h y s i z chemical research. We consider six topics in measurements methods: (1) acquisition of data, (2) data refinement, (3) numerical methods, (4) significance, (5) error analysis, and (6) reporting results. The utilization of a minicomputer (DEC PDP 8/L) having 8 K core, with oscilloscope, x-y plotter, and tape cassette program storage peripherals, in the performance of 19 experiments in the one-year (one credit) course having an average enrollment of 50 studentslauarter, over the past f ~ u r - ~ e a rwill s be described. ~ l t h o ; ~ hcomputer instruction per se is not considered advisable within the ohjectives of the course, familiarization and utilization of the computer as a tool are essential. Other course objectives including the student credit/work load which are enhanced because of the computer were discussed. Copies of the programs in FOCAL are available from the author.
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The Small Programmable Calculator in General Chemistry Laboratory (Wang 500 and 600)
Robert H. Bell, University of Richmond, Richmond, Virginia The Wang programmable calculator, over a period of three years, has been graually introduced into the general chemistry laboratory. This process divides into four phases which are: (1) checking student. laboratory results; (2) on the spot analysis of the laboratory results with sugges-
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tions for immediate improvement of laboratory technique; (3) involving the student in writing simple programs of his own to solve problems; and (4) finally, the present state consisting of a combination of 1, 2, and 3 above. The many advantages of having programmable calculators present for students seem to far outweigh the few disadvantages. Problems usually assigned for general chemistry laboratory can be revised to make the fullest use of the various rapid computing capacities of the programmable calculators. Since this type of computing has not been available for general chemistry laboratories in the past, this is thought a step in the right direction a t a reasonable cost. This new tool has not onlv been found useful hv the student, but the chemistry faculty has been active in learning and developing new techniques for its fruitful use in the department. The tentative conclusion is that the use of the Wang or similar programmable. calculator in the general chemistry laboratory can he for the student and faculty a new challenge adding depth of understanding and stimulating increased thinking about quantitative chemical problems in the general chemistry laboratory.
Computation in an Investigative Laboratory Program
Stuart M. Rothstein, Brock University, S t Catharines, Ontario. An investigative laboratory program is defined as a set of experiments which focuses upon the process of investigation and exploits the uniquesuitability of the laboratory for small-group instruction. The following are important steps for the investigative process: (1) question, (2) alternative answers, (3) strategy, (4) information, (5) synthesis, (6) conclusion, (7) generalization, and (8) prediction.1 Generally a traditional laboratory takes the student through (41, and the instructor has faith that the student can carry out the synthesis, etc. As a contrast, with a data reduction facility available, all these steps may be completed in a single session. Investigative laboratory courses have three aspects from a com~utationalviemoint: elementaw, intermediate, and advanced. The role of a programmabie calculator in these aspects is discussed, with the first being emphasized. As an example, an investigative laboratory program for a special three-week summer course is discussed. The experiments involve the synthesis, characterization, and kinetics of [Co(NH3)&IIZ+.Z Robinson, F. G., et al., "Inquiry Training." Ontario Institute for Studies in Education, Toronto, 1972. 2 Angeliei, R. J., "Synthesis aud Technique in Inorganic Chemistry," W. R. Saunders,Philadelphia, 1969, pp. 13-30.
