Chemistry Tutorial Programs on Display Terminals Computer-aided instruction (CAI) continues to become more prominent ( 1 3 ) . Contemporary CAI hardware and svftware has graphics and display capabilities (4-6). can "talk" (7) and will play a greater role in learning in the future (8). Sugarman (3)notes that a major obstacle toevaluation of CAI is that "learning is still in its infancy as a cognitive science, with or without computers." Empirical studies have shown the value of CAI, nonetheless, (1-4,9,10) and its use fur lab prepamtian is well demonstrated (5, 11). We have developed several CAI programs for display terminals used with a general purpose computer (12). Display terminals suffer from law resolution and a decrease in decision effectiveness has been reported in another context as a result (13).Despite this, the advantages of dynamic displays or graphics is clear ( 6 ) . Pmgram AR, like similar programs (4,5), prepares students far labs involving standardization of a base solution. The student chooses the volumeof hase to be put in the buret, is led step-by-step to the mass of acid required, and then performs the titration. The program displays the level of buret, buret reading and milli-equivalents of acid and base for each addition and prevents the student from overshooting by requiring gradual additions. Program BALgives practice in reading weights by clearly showing the relationship between the digits in the mass and their magnitude and their representation on the analog balance scales. After this practice, a sequence of weighing two solid samples by difference may be done using single character codes for halance operations. Pmgram ABT calculates a pH curve for titration of a polyprotic acid by strong hase (14). The student locates the equivalence pH and volume, calculates the acid strength and chooses an appropriate indicator. Line printer copies of the displays are available for further study from this program by means of a subroutine which interprets the cursor controls (12). Generally speaking, students have been enthusiastic about using these pmgrams largely because the activity in the display maintains interest. The consistent use of brief, unambiguous responses, previously noted for PLAT0 terminals (9), is important to prevent confusion and also because most students do not type. A lack of superscripts on inexpensive display terminals makes it necessary to specify units in questions which require numerical answers. No matter what efforts are made to make the programs easy to use, we have found that a student's initial experience using CAI can become frustrating because of unfamiliarity with keyboards, logging-in etc., unless instructors are available for help. Further information on these programs and the display library for ADM-3A terminals (121, which has some features peculiar to the system, is available.
Literature Cited (11 Mnwe. J. W. and Cn1lins.R. W.. J. CHEM. EDUC.,SG, 140 (1979). (2) Lowe~,S..Gerhold, G., Smith, S. G...luhnsnn, K. J.. and Muure. J. W., J. CHEMEDUC..56.219 119791. is1 Surarman, R. IEEE Sprdrum. 29 (August 19781: 44 (Sept. 19781. (1)Smith, S. G. and Chsbay. .I. CHEM. EDUC., 54, 745 (1977) and ref. ,L".&..
(6) Rc>hinaon,A. L., Science. ZW.719 11978). (7) Shoiwnud, B. A . l n l l J. Man-Mochine Studies. 10,669 (1978). ., and Pspert.S.. Conduit P i ~ e l i n e 3.3 , (19781. (81 B U ~ ~ . ALuehrmnnn.A.
Dalhousie University Halifax, N.S.B3H 453 Canada
(91 Hansen, W. .I, Dozing, R. and Whitluck. L. R.. Inti J. Man-Machine Sludirr. 10,407 119781. i ~ l .(October 197'21. (101 Atkinmn. R. C.. Anwricun I ~ q r h u l r ~ 921 ( I l l Cavin,C. S.,Cauin E. I)..andl.a~~:wrki.J..I.,.I.CHEM. EDI!C..55,Mi2 (19781. 1121 Jones. W. E. and Warsun..l. S.. C u m p u l ~ r sin Chrmirtr).. in press. CDC fi40O (NOS 1.31. The prl~gramswere written in Rntran. (I:li Kozar. K.A.andDickson.O. W.,Inr J. M~cn~Mor!~iri~.Sf~dirs. 10,496 ,,O"",
M. Heit W. E. Jones J. S . Wasson
Volume 56. Number 12, December 1979 1 787
