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freshman and organic chemistry enrollment, more than 2000 students. All programs are written in DEC BASICStudent Sign-In Each student in freshman, organic, and physical chemistry signs himself into our records as oart of his first week's assignment. This ensures that each student knows how to gain access to the timesharing svstem. While many of our students have worked with comp;tek since grade schoil, for others this is their first computer experience. For the latter, sign-in overcomes the first barrier to the use of our other programs. Sign in also places the task of entering student names and identification numbers in the hands most likely to get these data right. Before sign-in can begin, siin-in data files must he set up within faculty computer accounts. Well before the heginning of each quarter, the system manager opens a master directory, where information is kept showing which faculty computer account contains grade records on each course and section. The directory is not directly available to either faculty or students. All faculty and student programs that use the directory are run in compiled form only. The location and name of the master directory file are confidential. The manager, through a management program SIGMGR, can inspect and alter the directory as required. Next, each faculty member runs a sign-in setup program SIGSET. Course numbers and sections are entered, plus the (confidential) names of the sign-in data files. SIGSET also handles entry of data-file names used by the programs MYGRADE and PROBLEM, to he described later. SIGSET generates individual four-letter codes for students and prints slips to be passed out. These codes are used by other programs and also prevent pranksters from signing in fictitious students (a prospect locally called the "fraternity mascot problem"). The second, third, and fourth letters of each code the system generates are consonants. This avoids the accidental generation of objectionable four-letter words, and at the same time reserves a number of possible codes that faculty members may assign without checking for duplication.
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c a l c u l a t i o n #8
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Figure 18. Description case statement. conveniences in languages that do not permit the nesting of subroutines. A copy of this program in semi-structured BASIC-PLUS can be obtained on request from the author. Each request must he accompanied hy a large, self-addressed envelope and a $1.00 postage and handling fee. Requests from outside the U S . must he accompanied by $2.00. Literature Cited (1) Higgins. D, A,. "Program Design and Construction? Prentiee~Hall,he., Englewood Cliffa, NJ, 1919. (2) 0r1, K. T.;'Structured Systems Development," Yourdon P~ess,New York, 1977. (3) Wamier, d. T., "Logical Conatmctionof Progarns: VanNostrand Reinhold Co.,New
A Multipurpose Computerized Class Record System H.
Bradford Thompson University of Toledo Toledo, OH 43606
A good timesharing computer system can he a great asset in the teaching of chemistry. The chemistry department at the University of Toledo uses a variety of instructional programs at all course levels from freshman to graduate. This is, however, not the extent of the timesharing system's usefulness. We have, over the past three years, developed a class record system which performs many functions for both faculty and students. Among these functions are the following: Introduction of students to the timesharing svstem: Input o f student names into faculty grade r&ds h i the students themselves; Gradekeeping, averaging, summation, comparison, and reporting, based on a versatile gradebook program; Continuous access by students t o their grade record and standing; Distribution t o students o f exam scores and other class, group, and individual messages; Collection of departmental grade records; Course orereouisite checking:
The system consists of fifteen programs, working within the DEC1 PDP-11 operating system RSTSIE. The system is supervised entirely within the chemistry department; none of the programs or records descrihed are managed for us by the computer center. Grade records are kept for our entire
Ready
Course No. please? 422 Glve me your 4 - l e t t e r code, please: Last name, please7 *LPLLPLSPCI F l r s t name, please? IPT Is your name JOY JOHNSON7 1
YES o r N O 7
9 - d l g l t s t u d e n t number, please7 9 - d l g l t number, please (Don't u s e a n y commas.) 9 - d l g i t student number, please7 U& 848 00 3533 Is t h a t c o r r e c t 7 Y
Recorded 29-Apr-82 05:43
PM
Don't f o r g e t t o s l g n o f f (say B Y E F ) . Thank
you a n d good afternoon.
Ready
' DEC. PDP-11, RSTSIE, and BASIC-PLUS are trademarks of the Digital Equipment Corporation. Maynard, MA. The programs are copyrighted by the author. The BASIC-PLUS text will be furnished to college chemistry departments for individual use, for a charge to cover duplication. 352
Journal of Chemical Education
Figure 1. Student dialog with the program SIGNIN. Items typed by the student are underlined. Notethat the student code does not echo (is not printed)asit is
entered.
Ready c o u r s e N O . p l e a r e , Uz G I V E ME Y O U R 4-LETTER CODE,
GRADE B-
A S S I G N E D 02-Mar-82
PLEASE:
B A S E D ON G R A D E t i >
J
Exam i l l g e n e r a l l y much b e t t e r t h a n Exam I t : 3 1 4 ot the c l a s s t u r n e d I n p a s r i n g e f f o r t s . H l g h : 7 6 , L o r : 19. M e d l a n : 5 0 . L e t t e r grade tr your estlmrited progrers, a s s u m l n g Exmm I 1 t o b e nontypical i n m a r t cares.
Lower+ t a r g e t s c o r e r t o r :
I1
Although students never use GRADES, they quickly become aware of one of its important options: the production of MYGRADE grade report files. Via these fdes, using his private four-letter code. each student can eet a summarv of his own scores (but no one else's) as thesewscores appear in the instructor's grade file. The instructor chooses which scores are to be included. Any currently assigned letter grade is alsoreported. Messages can be included with the grade reoorts. ihsurge tiles itk, prepred b? the t;wuIt~~uemi)er\binp; text ~ d i t wand m;n Ijc. ;idorei.ed 1,. tht entireclaj clr to indrvidual students or groups of students. A typical student dialog with MYGRADE is shown in Figure 2. MYGRADE has many uses. I t allows a student to check whether his record of his grades matches his instructor's record. It provides a channel for rapid distribution of grade information. Perhaps most important, MYGRADE can he used to give students frequent evaluations of their progress.3 MYGRADE is hy far our most heavily used program. The Prerequisite Check System
Our denartment enforces course nrereauisites. In this we find ourselves totally on our own. 0;r stuient records office will not check orereauisites for us. and advisors freauentlv
Joy:
P l a a ~ esse me some +,me t h 1 5 week. Red"
Figure 2. A MYGRADE studem report. The above is an actual repat via rnygrade, altered to protect student identity. A: Standard MYGRADE report. B: General message. C: Individual message. Items typed by the student are underlined.
A typical student dialog with SIGNIN is shown in Figure 1. Since (as noted above) SIGNIN is the first nrozram that " many students have ever run, it must he short, simple, and as foolnroof as oossihle. SIGNIN looks for errors that we find students make. For example, a stndent will insert his fourletter code in nlace of hisname. or tvoe letters in nlace of his student number, or type the letter-0 for zero, o; strike the return kev before entwine anv character. In addition. SIGNIN prints back the entered &t&d asks the student to verify it. Almost all students sign in successfully, with, of course, a great deal of mutual assistance. At this point we have gotten the student over the first obstacle to usiur our instructional nrograms: he can communicate with thecomputer. This initial step, although small, is one many students never take without incentive. We reinforce this introduction later with the program MYGRADE. The faculty member can check the sign-in process a t any time via the urorram SIGCHK. The student list can be A
bers, and codes for the gradebook program. The Gradebook Program
The gradehook program GRADES performs a variety of record keeping and manipulation functions. Numerical scores can be entered from the keyboard or from records produced by other programs. Scores can be summed, with weighting if desired, and with the option of dropping lowest scores. Excused scores can be included in sums by proportional prorating. Raw grades and sums can he placed in any of 30 columns. The results may be displayed or printed, in the original order or sorted on the basis of any column. Letter grades can be assigned by hand, or based on any numerical column. Help messages are availahle for all options. A companion program, GRATAB, provides grade tahulation, means, quartiles, and histogram-type printout or display. Grades from individual sections can he analyzed separately and in combination by GRATAB-twolevels of totalling are provided.
grade sheets. Within the prksentiystem, however, we have turned much of this iob over to the comouter. At the end of tach qmrter ench in-tructm p ~ ~ this - : course gradas inti, his ~r.idebwllitilt iind then run: ii vruLrnni I'IIEREQ, which inserts this information into a master record for the course. PREREQ is very simple and fast to run. The prerequisite data are then used during subsequent quarters, through an option in the program SIGCHK. Although our present computerized records go back little more than a year, about 90% of the prerequisite checking is now done this way. These grade files have other uses: for planning purposes it is useful to he able to track populations of students through our course sequences. Ours is a municipal university with a large part-time population. A minority of our students follow any idealized course program from beginning to end. The Problem Program4 .A t n u p r nwd (,I' nuiny it~idt.tit.I S c ~ t e n j i drill v ~ in routine nuiiieri,;tl irrwhit I)1 n 8 ~ l i 1 1 1 . . iw l'1
