CAI Support Modules in FORTRAN and BASIC
State University College Brockport, NY 14420
programs written in I-FORTRAN. This paper described how CALCULATOR MODE capahility can he achieved entirely with I-FORTRAN. Another obstacle to writing good interactive lesson programs in FORTRAN, or any other computational language, has been the lack of as opposed to an authoringlmguage (4), good procedures for interpreting student responses and making branching decisions hased on these responses. In this paper we will also discuss a strategy for building a fairly flexible response analysis scheme into interactive lessonsystems while leaving the "driver" programs easy to read and modify. These routines are compact as well as powerful; and their implementation on other computer systems should be fairly straightforward.
Bhairav D. Joshi
Need
State University College Geneseo, NY 14454
Being teachers of science in general and physical chemistry in particular, we feel it important that our lessons for CEI should frequently ask the student to actually solve problems and that the student he asked to give numerical answers to these problems (5). These prohiems would he relatively short-much too difficult for mental mathematics but readily solvable using typical hand-held scientific calculators. Incorporation of such questions into CEI materials can he troublesome for hoth the student and the author. Consider the ways in which a student might want to react when confronted with a question like the one in Box 1 (taken from our Particle in a Box lesson system). Such a question is intended to provide practice in using the particle mass, box size, quantum number, energy relationship, and also to give the student an appreciation for the magnitudes of the variahles involved. Most students will either know or quickly deduce how to obtain the answer. However, they will in many cases need a "tool" in order to perform the required computation. Our calculator mode facilitv is iust such a tool. In order to motivate the" &dent and keep his attention focused on the lesson, other reasonable requests such as "give me a HINT, can I REVIEW that? show me the ANSWER, SKIP this item," etc. should also he recognized and complied with. This is very important from pedagogic point of view. The lack of a carefully designed response analysis procedure can he most annoying to the student, and thereby frustrate the intent of the entire interactive package. We have found that
The two articles that aouear below describe Fortran and
and Pieces, 9
Computer-Enhanced Instructional Materials for Interactive Fortran James E. Eilers and James Cronin
This article grew out of papers we presented at two recent professional meetings ( I , 2). On both occasions we were pleasantly surprised at the interest in using computers for chemistry instruction and at the extent of the interest in the actual "nuts and bolts" aspects of creating good computerenhanced instructional materials. Naive newcomers to instructional computing as well as sophisticated veteran enthusiasts wanted to know more about our strategies for (1) incorporating a calculator mode within FORTRAN programs, and (2) response analysis during interactive sessions. This paper presents our approaches to these two important prohlems. Background and Goals
Sometime ago we decided to harness the power of interactive computing to help our physical chemistry students learn beginning quantum chemistry. We felt that quantum theory was eminentlv suitable for our first maior effort in the Computer ~ n h a n c e m e nof t Instruction (CEI). In other chemistry areas a student is traditionallv riven a second chance: he can from lectures, and to test his ability to use these concepts. N O such experimental or discovery approach then existed for il-
SYSTEM-an extensive, integrated collection of computer based educational materials designed to enhance student abilities to appreciate, understand, and apply the concepts and techniques of quantum chemistry (3). Having a fully Interactive FORTRAN (I-FORTRAN) system available to us, beinn interested in ~ortahilitv,and of our materials with students, we came to realize that the lack of a calculator mode was a serious deterrent to the use of FORTRAN, or any other comp~lerlanguage, for CEI. Rather than rewrite our materials for an mterpreter language or learn to load and call an interpreter from a FORTRAN program, we chose to create a calculator mode capability for use with
Box 1. Question: Consider an electron confined to a 30 A box. How much energy. in Joules. would have lo be provided by a photon in prder to "excite" this electron from the first energy level to the second energy level? Possible Responses: (1) the correct numerical value. (2) an incorrect numericai value. (3) "you must be kidding. I'll be back in an hour with my calculator and textbook.'' ( 4 ) "Aw come on! Give me a hint." (5) ''I give up. WhaVs the answer?" (6) an obscenity.
Volume 59
Number 3
March 1982
209
Table 1. Calculator Mode Operationsa Process
Process (Replace x by)
Operation ( s y r n b ~ i ) ~
Operation ( s y m b ~ l ) ~
DYADICS
MONADICS
Addition (+) Subtraction (-1 Division ( I ) Multiplication ( r ) Exponentiation Interchange (X)
Natural log (L) Common log (L)= Natural antilog (E) Common antilog (t) Square root (R) Reciprocal ( 3. By h a many J o u l e s da.s the intema, energy O f a i y s t e n i n r r e a s * xnpn -13.1061 i a l o r i r i o i n e a t a r e extracted iran t h e i l r t a m -.917614 l l i L l b m O l p h u P I O f *Orb d m added t o t h e nsTaml NO" I n p u t YO"? ""meilcal answer. 1W~L ,GO TO /",A t i t h e r enter the u p i e i i i o n you rant e v a l u a t M o i l i T . TO C3LC"LaTII 'i.+i.,l, 'I' n o t found i n l i i i n c e ' 1 ' ; try a w l "
,
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in one oi the
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COMPUTER
EXECUTOR
Flgure 1. Subprograms of PCM ~ 8 t valid h access paths Double arrow implies aUtOmatlC return.
212
Journal of Chemical E d u c a t i o n
Figure 2. Sample session of PCM; editorial comments (located on right) have been added for further explanation. Upper or lower case entries are valid input.
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