The Application of Computer Technology in the Assessment of Large Undergraduate Classes Ann Mihkelson, Gary D. Willett, and Allan J. Williams Sydney University, Sydney. N.S.W. 2006, Australia The application of computer technology for more effective teaching is a fast-growing area ( 1 4 ) .This paper reports an application of computer technology to assist testing and grading of large student populations. Computer marking of tests through optically read marksense sheets or cards is not new. Because of reading deficiencies of optical scanners and the cost of computer staff to handle the mark-sense sheets, special portapuuch cards were designed. These cards can be processed routinely at a batch station by laboratory staff having little knowledge of computers. The system not only allows cheap and reliable marking but also can accommodate a variety of tests. Such grading at Sydney University efficiently and regularly returns results to some 1800 first-year students. Computer cards of snecific desien and color are nroduced hv I.B.M.'. Each card has sectiok with perforate'd tabs whilh can be pushed out with a pencil by the student. The cards are read and processed on the University's central computer (CDC Cyber 170130, NOS 1.4 software package written in Fortran, Pascal, and Cobol). The largest program has a maximum execution field length of 74,400 Cyber 60-bit octal words and uses 6.5 seconds of central processor time. The turnaround time for the results depends on the nature of the assessment: from one hour for quizzes to one week for a laboratory assessment that depends on the statisticallv averaged result for all students. particular student's progress can be reviewed using the terminal. Students, however, have no perusal access; their results are posted. Since the computer cards can he tailor-made, the system can be adapted to suit the purpose. The following discussion briefly describes how we have applied it. During the year (a 30-week course), a total of eight, 1015-minute, multiple-choice, laboratory quizzes are conducted to assess understandine and to motivate students to nrenare for laboratory classes. ~ultiple-choicetesting is also k e i for lecture material to reveal problems in understanding that can be remedied before new, dependent concepts are taught. Successful aunlication of this tvne -. of assessment has been reported by 6 t t e r s h a l l (5). First-vear undergraduates are required to hand in 24 problem~solvingassignments of about s'ix questions each, from which selected questions were previously checked (hut not marked) by tutors. The assignments promote student motivation, but 1800 weekly assignments create a considerable amount of grading work. Some of these student questions have been used for programmed instruction using C.A.I. (6). Othen have been re-written in multiple-choice-form and can be processed in a day. Students carry out two practical assessment exercises, molecular-mass determination and organic unknown identification, and enter their results by a known code.
I I.B.M. Australia supplies portapunch computer cards at a cost of $10-30 per 1000 cards. Once-only costs of $55 for card design and $50 for backing rollers are required.
For molecular mass determination students submit a card indicating their determination of weight, titratiou value, and calculated molecular mass. Allowance is made in the Fortran program for students who misuunch information but still s u b h i t a correct calculated vaiue. Compared with conventional hand marking the turnaround time has been reduced from several weeks to one week. A similar procedure enabling laboratory grade reagents to be used for a satisfactory assewrnent has been reported (4). For organic unknown identification students submit a card reporting their results for elements present (sodium fusion test), functional group (by numbered code), melting or boiling point, and finally identity of the unknown itself (using coded input). The Fortran program contains a variety of flags to locate misnunched cards. Results are available for nostine wlthin two hours. I.ater, statistical analysis provides information cuncernine" the relative difficultsof identification of the compounds for students. I t costs about 50 cents ner student assignment for hand marking. A cvmputer card rusts half a cent and pruceshg H I I O U ~ 2 cent^, which is S't the cost of hand marking and ahout one-fourth the cost incurred using mark-sense sheets. Computer marking has several advantages. It provides a rapid return of results to students and effectively reinforces the learning process. Misconceptions may be quickly clarified, a factor especially important where the knowledge forms the conceptual basis of other material about to he taught. Computer grading is labor saving and one twentieth the cost of hand marking. Statistical information is easily accessed to establish test validity, question reliability, or purity of chemicals, to demonstrate student performance, and to correlate analyses. The use of mark-sense cards instead of portapunch cards is recommended bv the authors. as utilization of card mace and a reduction inproduction cbsts can he achieved. ~ & b stantial program revision could integrate a CRTihard-copy terminal mix to improve feedback quality and reduce turnaround time throuah an "Eves Onlv" urivacv scheme uer. . mitting student access. Further information regarding the computer cards and programs may be obtained from the authors (G.D.W.) on request. Details of the programs can be supplied on 1600 bpi, 9-track magnetic tape. Acknowledgment We wish to acknowledge the support of N. S. Hush, A. J. Harle. R. K. Pierens. and D. Radford in carrvine out this work. s the The kbstantial programming aid given bye. ~ u r r o w of Sydney University Computing Centre is also gratefully acknowledged. Literature Cited 11) "CAL in Cuildfi,rd."(coBmnl.iWdvc. Chem.. 18.99 l1961), (2) Heerer. A. E..and Went, D.,Edur. Chrm., 18.104 (1981). (31 (ir.mvoa, P., Educ. Chrm., IS, 107 (1981). 4 (dl Smilh.S. R., Shur,R.,and 0onuhue.P. C., J.CHEM. E ~ ~ c . . 4 2 , 2 211966) ( 6 ) Talershall. H. W., Chem Rritorn, 16,262(1980). Ifil Mihkelsun.A.,Educ. Chem., 19.24 119821.
Volume 61
Number 7 July 1984
631
