Computer-Assisted Instruction on a Microcomputer Stanley G. Smith University of Illinois, Urbana, IL 61801

Relativelv inexaensive microcomouters make i t oossihle. with appropriate Boftware, for largeLnumhers of &dents td use computers to help them learn chemistry. Such micro- computers are being used in rapidly increasing numhers to provide direct tutorial instruction, pre-lab simulations, col- lection and processing of lahoratory data, lecture demon- strations, class management, and control of videotapes and videodisks. As the numbers of computers in schools increase, both the number and quality of programs also seems to he . . . increasing ( I ).

What Can a Computer Do? Although computers are often credited with mvsterious

powers, the major features which are important to education are their ability to put text and lines on the screen, collect keys pressed on the keyset, do calculations, follow pre-stored procedures, and store information. Of course, a microcom- outer does these thinas verv raoidlv. Pictures which are drawn . . - on the screen, erased, and redrawn in a slightly different po- sition orovide an element of animation which can reoresent the mechanism of a chemical reaction, for example.

Since the text and figures shown to the student can he the result of an analysis of the keys which the student has just pressed, i t is possible to write programs which convert the microcomputer into an interactive medium for instruction unlike anything possible with a textbook. Such microcomputer systems can hold a dialog between the student and the author on most anv tooic. The interactive character of instructional material aLd the ability to do animations makes the medium very different from a static printed page of a hook and calls for very different instructional designs.

Examples The combination of lines and text in the form of a simula-

tion of a traditional titration experiment (2) is illustratrd in Figure 1. Such simulationsare useful hefore studentsgo to the laboratory because they allow the student to focus on the critical elements of the experiment without the distractions inherent in typical student laboratories.

Laboratory simulations do not have to be limited to ex- periments which students might do in the lahoratory. Figure 2, for example, is taken from a program in which students try to olace unknown elements on the Periodic Table hased on thck chemical and physical properties (3). As illustrated in this figure, some of the tests necessary to do this analysis can he too hazardous to he done hy students in the lahoratory. Simulations can therefore give students the intellectual ex- perience of solving lahoratory type prohlems that they might not he able to do in the lab due to potential hazards or limi- tations of time and cost.

The ahilitv of the microcomputer to manipulate characters rapidly makes it possihle to p r k i d ~ * 3tudenG with a powert'ul tool to help them learn the names uf thin0 ( 4 ) . Firure 3 shows a typical response to an incorrect name for sodium chloride. The student is advised that the ending should he -ide instead of -ine. Furthermore, the markup symbols under the answer show where letters have been transoosed and indicate that an extra "s" has been added a t the edd of sodium.

Very detailed help with numerical problems can also be provided to students. Figure 4, for example, shows a typical

864 Journal of Chemical Education

gas law problem in which the student is asked to calculate the new volume of a gas if the pressure is changed from 4 atm to 1.33 atm (5). The student creates the appropriate equation by pressing the left and right arrow keys on the keyboard to hiahliaht one of the hoxes a t the bottom of the disolav. and . 0 ,

th in pressing N to enter the quantity in the numerator or D to put it in the denominator. In the example shown here, the computer points out that the student has inverted the pres- sures in setting up this equation. When used this wav. the computer makes it easy f i r students to practice setting up problems and to receive specific help on errors.

Less-structured prohlems such as multistep synthesis may also be carried out on a microcom~uter which has been pro- grammed to carry out typical functional group changesa(6). This is illustrated in Figure 5 where a student has proposed

You v e n t p a s t t h e end-point.

Press RETURN t o s t a r t ouer.

Figure 1. One display from a lesson which allows shldents to practice a tlbation experiment with a computer simulation. (Reproduced with permission of the copyrigM holders.)

React ion o f XA u i t h ua te r .

Press I l l : I I l l I I t o continue.

Figure 2. Test of the reaction 01 an unknown element with water. (Reproduced with permission of the copyright holden.)

a svnthesis of orooanoic acid bv selectine reaeents from the - h i e s at the bit& of the screen. This type of program allows the student to trv several different wavs to oreoare a given . . compound.

Uslng Computers for Teaching Although the use of microcomputers in teaching is relatively

new, mainframe computers have been used for teaching for about two decades (7). Computer-assisted instruction, or CAI, using the PLATO' system, for example, has been a required part of an introductorv general chemistrv course, the first . - semester organic chemistry course, and organic chemistry laboratorv courses a t the University of Illinois for over a decade. ~icrocomputers with instructional material on a floppy disk are now being used in large numbers of schools. Connecting a classroom full of microcomputers to a single hard disk makes i t easier to manage large numbers of students, but the amount of material which is available for use on such networks or clusters of microcomputers is still very limited. As the few examples shown in Figure 1 to 5 indicate, a wide

range of types of instructional material can be presented with a microcomputer running on a diskette or a network/cluster system. Although laboratory simulations are attractive, one would probably not simply replace all laboratory work with computer simulations. Often, however, the options are not that simple, and given the choice of no laboratory or a simu-

T y p e t h e name o f t h i s compound.

> soduins chlorine IIt~II1::ll r L x - -

chlor:ii, KII II::!! not c h10r:ii. I~II

Flgure 3. Example of wrong answer feedback to a student on a nomenclature bill. inveRed l m w , extra leners ard wnng l m w a r e mahed under the answer. (Reprcduced with permission of the copyright holders.)

A gas occupies a volume of 28 1 a t a pressure of 4 atm. Yhat uould i t s uoluue b e a t 1.33 atm pressure?

(1.33 atm) (28 1) " = . . ... . .. . . .. .. .. . . .. . .. . . .. . ... . . . . . . . .. . .. . . .. . . .. . .. . ... . ... . .. . . .. . . .. . .. (V atm)

p2 - P You used - anstead of A! PI p2

Press c t. N. D. E. RETURN

Flgwe 4. Part of a lesson ideal gasas, The shldentgeneratesthe equation lo solve me ~roblem bv ~ressino the anow kevs on the kevset to hlohlioht a varticular . . - - box'and then oressino ti to enter the iuantitv In & numerator or D to Dut it in - - - - - ~~~ - ~~ ~ . . me denammator Here the stwen has set up the eqdat on incarectiy and Ib appropriate message has men printed an the screen. IReprcducsa w t h per- mission of lhe copyright holders.)

lated laboratory it is likely that the simulations are preferable, although a combination that uses the best features of hoth would be the best (8-10).

Just as pre-laboratory instruction on the computer helps prepare students for actual laboratory work, pre-lecture tutorial programs can also help students be better prepared for lectures and class discussions (11). Incorporating the computer into the classroom presentations is also very effec- tive and allows the instructor to illustrate concepts with ani- mations, to show the results of changing parameters in mathematical models, or to explore simulations which stu- dents can later study on their own.

Wrltlng CAI Writing CAI in chemistry requires that one be able to put

chemical formulas on the screen. This means that the com- puter system and associated programming languages should make i t easy to use not only upper and lower case but super- scripts and subscripts as well. The interactive character of CAI is facilitated by answer-judging techniques that include spelling markup, synonyms, and allowing extra words while excluding some other words from the answer. Although these requirements are very different from those associated with traditional computational uses of computers, there has been some progress in providing the tools needed to do these tasks easilv (12.13). To meet the vast needs for instructional pro- grams, however, new ways of putting programs togvt her need to he developed. Ideally, the computer should write the pro- gram underihe directiim of the 'uthur.

Although writing the necessary computer code to simulate an experiment or to tutor a student in some aspect of chem- istry takes a lot of time, the instructional design that develops concepts logically and provides help where needed is actually the most difficult part of the development process. Also, considerable attention needs to he devoted to the design of the student-computer interface so that it is hoth quick and easy for the student to communicate with the computer.

The Future Ultimately it is likely that students will simply have their

own computers, and computer-assisted instruction will be as commonplace as textbooks. Notebook-size computers that allow students to search stored information about reactions, reagents, and properties are already available.

The rapidly increasing computer power of relatively inex- pensive computers also expands the type of programs which students can use on an individual basis, and hence what is

P r e s s SPACE f o r more r e a g e n t s

Figure 5. Sample synthesis of propanoic acid from ethyl chloride. The student selects reagents from the boxes at the bottom of the screen. Other reagents are obtained by pressing the space bar an the computer. (Reproduced with permission of lhe cnpyright holders.)

.

Volume 61 Number 10 October 1984 865

1 COyH*

7-Help 8 - S t a r t Over 9-Done

2 LiAIH4

3 H3O+

4 OH-

5 H2SO4

covered in typical courses. The challenge for the near future (4) Smiths. G.,andChabay.~.,"ln~'gani~Nomen~lature,"co~~ess, w m t w o r t h , ~ ~ ,

is to find ways of bringing the computational tools of research 1982. (5) Chahey, R., and Smith, S. G.,"ldeal Gasas."COMPreas, Wentvorth, NH. 1985.

chemists into the classrooms. (61 Smith, S. G.,"Almhola," C O ~ ~ r c s s , wentworth, NH, 1980. (71 8mith.S. G.,J.CHBM.EDUC.,~?.M~\~ (19101. (81 Mmre, C., Smith, S. 0.. and Avner, R. A., J. CHEM. EDUC.,57,196 (1980).

Literature Cited (91 Wiegera, K. E., and Smith, S. G.,J. WM. EDUC.. 57,494 (19801. (101 Lagowki, J. J., J. ClceM. Eouc.. 61,32 (19%).

(11 Maare, J. W., and Mane, E. A,, J. CwM. EDUC., 61.26 (1984). (111 Chahay,R.,andSmith,S. G., J.CHBM.EDUC..S~,~~~(~~TI). (21 Smith, S. G., and Keane,E., "pH: Adds and Bases in Water," COMP- Wentworth, (12) Tenculr,P.. Smith, S. G., andAvner,R. A.,"EnBASIC,"COMP.aae, Wentamtb,NH,

NH, 1984. 1982. (31 Smith, S. G., and Chabay, R., "The Elements." COMPresa, 1982. (131 "Super Pilot."Apple Computer Company, 1983.

866 Journal o f Chemical Education