COMPUTERS AT STRSFOKD : AX' OVERVIEW

Patrick SUPPES Stanford University, USA

My objective in this paper is to gi1-e arn overview o1 the many different ways in which computers are now being used in universities, and also to give some projecticns fo r the future. I hestcn to add th.& the ,sense of overview here is not a srtatistical one. I shall, itn f m t , not make m y elfort to colhtle da-ta from a var',ety of universities, but rather will examine in some -detail the highly pluralistic use sf computretrs at Stanford, my own universipy. 1.t is generoallly recognized that in the United States, Stanford is among the research universitite.; making the most exitemive use of computers. Thle other twbo exatmples that immediately come to mind are the Massachusetts Institute of Technology (MIT) and Carnegre Mdlon University in Pi8ttsburgh, but the gove;.all scene in the Unirted Staties is complicated and highly plura- listic. No single university is doing the most in every direction. There ;.re ilrnpcxtayt and pioneering efforts that aam not duplicated elsewhere in any one 'of 25 or 30 miajcr unilvelrl3ties in thde coun.rt,ry.

I have organized thik paper in the fo,llowing way : the next sec- tion gives a broad overview of the ways in which cornputlem are iulsti- tutionally oqpnized ,at S&mford. The fclllcwing section, Sechion 2, dis- cusses the special role of networking and some of the problems that h.ave h e n encountered It1 impl~emcmting a natilsfjwtory network at a place like StanfoEd. Section 3 gives a survey of some of the different instructilonlal uses of cornputem :art Stanford. In Sedion 4 I t rwt in somewhiat unorle detail my own yeax oî sexperknce iin computelr+ssitsted instruction at Stanford and also, but to a lesser extent, my experienze in Amaricm secondmy schoofls. The finad sectison m&es some projec- tions about the future baed on my cument impressions of develop- inellbq thkt are taking p l ax !n the United Strltjes and other p=aIrts of the world ,at the present time.

1. Overview of Computers at Stanford

To bhe visijtor coming in from the ouitsidc, the trnain laldmi~nistratitve unit in charge of computers at Stanford thrat he would perhaps first en- oountm would be the Infomatiion Technology Services (ITS). ITS is

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COMPUTERS AT STAKFORB AN OVER\'IEK'

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-Ac=elerator Center (SLAC) which has very large computers as pan% of Its facilities for research in elementary particle physics. SLAC mainly uses large IBM mainframes. The computing fadi t ies ami8able at SLAC would- -alone exceed that ,at pro'kbly 75 to 85OlO, and passibly more of ilmc.rican universities. Secondly, -there is the Deplartment of Computer Scitence .which has major faci;littiles available, especially for resealrch i n mtificilal intelligence. T h w faeidities are run as a septarabe facility in the Depqtment of Computer Science. The Department of Computer Science has a variety of equipment. Until recently, i t has extensivel? wed DEC iequipnen4, but i5 moving increasingly l o a varl-iety o f recent n-mchines, especilally those well suited t o efficient execution of LISP programs. The Department of Computer Science is now n part of the School of Engineering, but I also list the variety of facilities available in the School of Engineering which are separate from the Lleparpnmt of Computer Science. I t is impor.t!mt, however, to emphusize thrak the \-c?kiety *of com*puting in the Scbotol of Engineering is even at this levcl, not organiad i n the Dean's Office, that is, ce~lltnally i n the school, but is dewnttmalized t o various departments of fthe School of Engineering. These decentralized facilit.ies in the various departments of the School of Engineering we used both for instruction and ceseBrch. I t ik fair to say however, that there is some tendency for the instructional faci- lities to be more ccnttralized at the school level than the research faci- lities. The variety of computer equipment in the various departments of the School of Engineering is loo great to survey, but there has been il very strong move tlo having a large number of personal computcrs :1\railable both for faculty and students. I

Next in size is the School of Medicine, which has extensive com- puter facilities primarily for research purposes. Many readers probably have heard of the artificial intelligenlce programs devellopecl at the Medical School for Medical Diagnosis stlch as MYCIN. but there are aìso extensive use of computer facilities for data analysis and a varicty of othcr purposes. Again these facilities are independent of other ndlministrations in the university. The School of Medicine has in the past used IBM mamframes mainly for data analysis and DEC 36-bit \vord machines, originally PDPlOs and later PDP20s, for the work in artificial intelligence. Given that DEC has terminated its line of 36-bit machines, the future is less clear but undtoubtedly the work in artificial intelligence will move in the same direction from the standpoint of computer facilities as that in the Department of Computer Science.

The School of Business has a centralized facility as part of the school with a staff to run computer facilities, but I emphasize again that this facility runs at a d>ecentralized level from the standpoint of the entire university. The Snchool of Business is essentially responsible Independently and without further eonsultatkm for the way in which this computver facility is run. The facilities are used fair both research :tad instruction. The School of Business is encouraging every student to have a personal computer. The use of personal computers is extensive. In addition, the central computing facility of the school runs two DElC

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To those readers entirely familiar with this pattern of funding, I should mention that frmm a legal standpoint the contra research are between various agencies of the federal Stanford University but, in actual fact, the researc constitute the substanti\-c basis for *the granting of the research are made by individual investigators, and these individual investigators really have the responsibility for raising the funds by making proposals to granting agencies, and also for g the use of the f,unds once they arme granted. The univer5it fiduciary respon- sibility, but not a substanti\-e research re y at the central lew.1, in the use of the funds.

h important problem fo,r a universi s 01% whic11 there is extensive computer usage is how various ers and terminals are to be connected. Fiftesen or twenty years e matter was simple ; there were (a relatively small number of computers with each computer supporting a number of terminals. On occasion an effort was made to establish direct communiclation between computers, but no general net- work was put in place. Not only on campus throughout the world, perhaps the central technical hardware a ware problem of dlata

* I have benefirted from discussion wiltth WLLliam Yaandt, Diwctor of the Stall- ford Netwoirking Staff, and Ron R ~ k f i s . a mem er of that staff with whom T have worked for many years.

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processing managers at the present time is establishing m efficient and relila,ble network.

The St.anf0x-d network has grown up in a diffmmt way than many that alre being installed at the present timcb, for it has evolved in a piece-meal fashion. The first ethernet networks were based on cxperl- mental 3-megabit ethernet hardware and software given by XEROX to Stanford. It was realized quite early that the expnsion of the ethernet as such to the entire campus would not be feasible. There werc t\vc; rcasons for this I-iew of the matter : first, the ethcrnct hardware did l>ot work well at distances longer than about 3 kiivlnetc~rs ; S~CO~XI, thc (Athernet was subject to various kinds of failure. These local failures :Iceded to be isolated so as not to disturb othcr parts of the network.

What Stanford did was to introdtwe a gatenray tcchmlogy. In Frin- ciplc - though in practice a little different -, each building addresses the nxin netn-ork through a gateway. This p t eway prslects the main network from points of failure in the local ethernet in a given buildin&.

The Stanford Gateway is a packct-routing device but the hardtmrc and software wcre spcciall>- designed k t Stanf9r.d. ,\L g ~ ~ k t v a y is capable ~f intercoimecting ui-, to iotlr cthcrnets, which consist of cxperimentd %megabit cthernets or standard 10-megalbit ethernets. There is, in principle, no limit to thc distance bt4ween gateways.

At the present time, the total number of gateways is 31 and the t:)tal number of subnets is 53, but it is e\-ident the network will cwn!inuc to expand. Also, by this time, most of the local ethernets ;wca standard 10 megazbitS.

Another fclature of the net are TIPS for terminals, whew ‘l’I!’ stands for Terminal Interface Processor. TIPs arc built a t Stanfor:l lvith the same hardware components as the gateways. 11 TIP uses Tclnet protocol software to establish communication between standard I~SCI-II termin& connected to tllc> TIP and conlputcrs attached to the nctwork. Thc Stanford TIPs are widely used. For cxa~nplc, nxmy OL the timeshiring computers do :lot interface any terminals directly, but only through thc ethernet at TIPs. There are approximately 2,OW terminals connected to the ethernet by way of TIPs and well over 500 different computers, with that number continuing to expand as a kwictp of pcrsonal computers arc added. .

Stanford has been the recipient of a large IBIL’I grant of equipment, the impxt of which I will discuss in more detail in the next section, but it is worth remarking that the IBM PC family is supported on the network by thc fact that the network supports the 3-Comm ethernet board which costs something like $ 500. The software supports both file transfers and protocols for remote terminal access. In the latter. case, it uses IP,!TCP which is the standard ARPA net protocol. Hoiv- ever, which

n about rcten t

most of the PCs are actually uws the same board. natural question about networks large numbers of terminals on past. What about saturation ?

interconnected on a local 11.3

is the same question thPt ariscs timesharing computers in thc

Thus far thc operational ex-

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3. Survey of Instructional Uses of Computers at Stanford

This survey will necessarily be superficial and not in any sense statistical. The widespreald different uses o f computers are so extensive in nature th:at 1 can only deswlbe them in a generai way. I have also excluded any attempt to describe the resclarch use o f computers which, it seems to me, is in m y case much better known from the scientific literature. To a fair extent, the suri-cy w i l l be based up011 uses that are being maclcl of the extensive equipment grant made by IBN[ to Stanford, but there is also extensive usc' of other compttter equipment. In fact, .:)me o f the uses described commingle tquipmcnt from various manu- fxturcrs. In any casc. my central p n t i \ to \tress the instructional applications.

I hai-c. organized this survey i n terms of the various schools at Stan- ford, which constitute the main admlnistrative organization of the university for instructional purposes. I lla\-e organized the presentation i n terms of decreasing c~nrollment : the largest school, the School of Humanities and Scicnces, comprises 27 acadcmic departments and 26 separate programs.

The School of Humanities and Scicnces

I begin with the Economics Department which hls under way an intensti-e development program for . the use of cornputers in hrgc en- rollment undcrgradcate courscs. Most of the wark consists of q u a l - titattve anaiysls including use of simulations. There are d s o a number o f lincur programming and other cwmotnetric statistical packages used by students in the analysis of data. The Economics Department and it-, students use c.sscntially 100*/o capacity of tht. IBM 4381, although there ;tre other users on the system. I mean that 10CO,o o f tlw cyclcs are Ixing used 24 hours a day, 7 days t\ weck Tllc Departments of Political Science and Sociology have a similar large-scale use. Students are doing studies o f various social phenomena bascd upon largc-scalc data files

ailable from the U.S. Census and o t h c ~ sources. E n contrast, the Ilepartnlcmt of Communications is using computer facilitics to improve video-editing tcchniqucs and also has an extensive use of microcom- puters by students for electronics story board programs for film and television and fcr data analysis. The Dclxwtmcnt of Psychology has an extensive w c of computcrs for indivdurilizccl instruction, especially for dcmonstre tion and simulation o f well-known psychological phenomc?na.

It should also be mentioncd that for all of these departments, the L:SC! of microcomputtrs for word processing is imrportant for large num- bers of students, both undergraduate and graduate.

I turn now to some sample IISCS from the natural wicncc depart- ments. In Physics. person31 cpmputrrs arc' being uscti in a theortltical astrophpics course for ncw . routse development. Extensive use by \tudents for both purposes of simulation and numerical computation represent a cehtral role for instructional use of computers in physics. In broad terms the uses are similar in the Departm.ent of Chemistry.

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School of Engineering

Here i5 a summary statement c d thc ~ a r i o u s ways i n u-hich the Engineering faculty arc using personal cornputcm for instructicnal pur- poses :

8 Develop homework problems @ Prepare and give demonstrations i n class * Prepare lectures Q Evaluate student computer programs Q Keep class records ea Supplement activities in the laboratory Q Perform calculutio!ls in the laboratory More generally, the School of Engineering has an intmsi\-c effort

now tn spread the use of computing facilities throughout the faculty

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and student population. The current rate of change is very high. Even five years ago there was a fairly limited use of computers for instruc- trona: purposes in Engineering : ten years from now it will be found tlrCrywhelre in the currictalum. Here are a few topics either th,at have been developed or planned for the immediate future by various faculty :

e Classroom demonstration of microwal-e circuit design * Lecture demonstration of fractures of materials * Interpretation of mass spectra 8 Interactive use of computers for decision making

9 Simulation of shock-tube experiments e Control labomtory experiments rolatcd to composite structurcs

Interfacing of computers to the operation of advanced smsors @ Providing simulation in theln?al-szience laboratory courses @ Developing a computer-aided design facility for VLSI chips

Demonstrations of energy-policy models

School of Business

The Shoo1 of Busines at Stanford is a Graduate School of Husi- ness, There are no undergraduate students. The bulk of the students take an M.B.A. but there is also a significant Ph. D. program. Here are <orne sample instructional uses that ha\^ been developed or are being develo~ecl by faculty :

e Development of case studies of decision-making under uncertaillty e Use of LOTUS 1-2-3 for simulation studies of pricing 9 Use of LOTUS 1-2-3 and other statistical routincs to analyze

eIntrociuction to Electronic Financial Reporting (to rcplace p ~ p e r personnel data

reports) Use of LOTUS 1-2-3 ta model corporate cash flow

0 Use of various programs for nonlinear time series analysis Statistical analysis of future prices and, in particular, applicL1- tions to multi-asset hedging strategies

School of Medicine

"here is already extensive use of computers as mentioned above for research in the School of Medicine. The current rapid change is in the use of computers also for instructional purposes. There are over 400 medical students currently enrolled, an additional 160 advanced- degree candidates, and more than 450 post-doctoral scholars, as well as the regular faculty. As in the case of previous schools, I list here a number of different projects by brief descriptive titles :

Use of personal computers in biostatistical analysis e Use of large-scale medical data bases now on line e Teaching pharmacokinetics and pharmacodynamics by computer

modeling

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of Earth ~~~~~~e~

The School. of Earth Sciences is a snsall

us cdses, I list hew somt typical tcac to the c3xtcnsiye uscl of computers in both

Modeling of geochemical thermudynarnics * Simulation and rnanagcmcmt of groundwater Tcchniques o f satellite ancl aircraft image prccessing

@ Dynamic simulation of geologic processes

4, My Qwn Teaching Experience with C

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I llave offered the- regular course entitled GIntroduction to Logic” en- tirely as a course taught by computers. There are no lectures or quiz sections, and all information is given to the student at a computer ter- minal. The course is offered each telm three times a year. We now llave experience with thousands of students and I will try to give you some comments about the course based on this experience. First, the students reach a pass level with on-the-average of 80 hours at the tcr- W I I L ~ ~ , that is, each student h,ts about 80 hours of connect time, but thc standamrd dcl\-iation on this mean is vcxry high. Sccondly, the students talw another 20 hours or so to do all of tlw work for an honor‘s grade. I-‘rom the standpoint of the use of computers, there arc important ftwturcs about a course like logic. The most important is that we have ,?reat flexibility in handling student responses. For example, \vhcn thc students give logical arguments, deri\-ations or procfs, their work is not matched against a stored ideal r ~ s ~ l l t . The program is organized to accept any valid argument or proof on the part of the student. Anyonrx \{-it11 ally cxperirncc on those matters knows that it is a mistake to have o ~ w single format of response when logical arguments are being given - - notlling can bc more stifling to the imagination and inventiveness of s t~dcnts . We want to encourage problem-solving as an individualized a:tivity 111 which many \-Friant ansrvers arc al1 deemed correct.

.\nothc>r feature of grcwt importance. in the toaching of a course likc) logic is that the work is highly intcw\r.tivc!. The screen of the tclrminal is not used as a page display on which endlr.ss amounts of exposition without any cxerc1scs to be done by the student are shown. The courw cmphaslzes a high lex-cl (:f interection and makes available to the \tudent a simplc, easliy used control language for making in- fcrcncvs. Here is an example n-11wc the studmt’s input is undcr1i:lcd.

5,8 AA (8) .r > 22 + r-! (9) y > z? + 10

Let me mention some additional fcaturcs. Errors on th6 pu-t o f the studcnt arc corrc3cd ilnnlcdiatcly with a message as to why the t’rror is indeed an error. I t is easy to generate individual messages again tic5 to applications o f specific rules c;f infmcncc\.

r h o n g the cxcrcises in thc logic cours(’ I like best the exercises on the stratcgy of selectlng axioms. It i \ oftcn easy for studmts to derive desired conclusions from givcxn prclnises or thcorcms from given axioms, but it is another matter to understand how one should select axioms to do a certain job. We hax-r a number of exercises labeled bbfinding-axioms exercises”. Here the student is given a list of elemen- tary statements ; for example, let us say 15 statements about the elelnc1~- tary geometrical relation of betweenness among points. His problern 1s io s-clcct no more than five o f tho statements as axioms and then to

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Axiomatic Set Theory

Let now turn to the swond course that I have taught in a similar fashion. The course in set theory has been offered on the same hasis every term since 1974. The general features are the same as the Iagic course. I mention just thosc special features that differentiate it. First of all, i t is a more advanced course and has a much smaller en- rollment. Ordinarily, the enrollment is about an order of magnitude less than of the l q i c course. This means that the enrollment will run

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from 6 to 15 students a term. In fact, my own view is that it is really courses of this kind that \ve should especially concentrate on teaching by computer because it is expensive to haw a regular faculty member oifer a murse to only six students. On the other hand, the stand-up lecturer, laoked at purely from a economic stmdlpoint, is a cheap teoh- nology when the n u b e r of students is well over 100.

I h e set theory courses are organized into a series of 650 theorems Because of the small enrollment, each student is given an individual set of thcorc.ms to prove and, of course, just as in the case of the logic, each student's proofs will be found to be dilferent from any other students. Inciecd, at this level of complexity, we would naturally be dceply suspicious of any two students clffcrmg exactly the same proofs for many of tllc theorems.

Of course, as I llave emphasized, the proofs arc much more com- p1ic:ted in set theory bucause of its more advanccd nature. The biggest intellectual cffcrt kas been put into de\-eloping a usable interactive theorem prover. We are able to prove the standard classical theorems in set theory now, but thew are \v ;tys in which we can certainly continue to improve. I do think that our interactive theorem prover AS probably the most sophisticated one in the world being used on a regular basis by students who are not programmers to prove non-trivial theoram.

OHC of thc things to have a sense of is the enormous variability i!. the kinds of proofs that students offer. Here is a small sample of 1,000 proofs. I shGw thc average length of proofs and number of lincs in the !cft-hmd coiumn. thc average of the minimum proofs, that is. we take the shortcst prcof given by m y student for a given theorem and now average thcse data across theorems, and finally the corresponding aver- age nnximum proof.

AVG AVC ML4N MIN MAX

15.0 3.5 5 L 7 Notice that the difference betwcen the average minimum and the

average maximum is momre than an order of magnitude. I should mention that we make regular use of a resolution theorem

prover, which the studlent can call to go from one step to another. The student is given 25 seconds of machine time to run this theorem prover, so one of the things that he must learn is what it can and cannot do. For example, it is not of any interest that the resolution themern prover is i n principle complete, that is, given enough time, it could prove any first-order logic inference that is valid. What is important is to get a sense of what can be done in a limited amount of time and lvith limited resources of the computer. Students become fairly good at cali- b r a h g what to expect.

Differmtial and Integral Calculris

In spite of my statemient that we should concentrate on courses with small enrollment, for a reason to be explained in a moment, our

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current effort is to roduce a ~ o I ~ ~ ~ t ~ r - ~ ~ ~ $ e ~ Course i n th? and i 11 tegral calcul undcr raduates in

lace ita-in l l igll scho students who are

c, I should comment, done a t the undcr-

graduate level in the uni\wsities rather than in high schools. The main topic that we are addressing i n the d e ~ ~ ~ l ~ ~ ~ ~ n t of this cou2rse is exactly the feature stressed i n he logic and set theory courses, mmely, a stress on offering a rich intc active structure to the student to do all t1 le standard deductive work.

In thc case of' the calculus course, thcre ar? special problcrns of flnding the right internal formalization for t h t informal language and infcrcnces customarily used in the course. h \vil1 not try to s tllc pa~.ticular technical problems we arc now wrestling with. l o say that our objeetivc, howel-cr, is to chan ils littlt . as possible and %o offer a course that is standard in appearance as far as the mathematical cxprcssions go the inference rules art' close to what is to be found in a standard te

Ont unportant feature is thcb extensive olic calculat~o~s of an algebraic and calculus sor:. Therc art' n o w extensive programs, e.g. REDUCE and MACSYMA, for making such computations for en- gineers and scientists ; our problem is to build a highly interactive symbolic calculator that students can use effectively in this coursc. The stress on the interaction and thc stress on the use by students meall that n-e must do a lot of things in a way that is different from the way things are done in REDUCE or NIACSYMA, but I shall not enter into the details here.

I do want to men'tion that the striking difference found in the cal- culus course, when compared to the logic and set theory courses, is the extensive use of graphics. Fortunately, we are preparing this coursc at a time when good graphics are available at a reasonable price corn- pared to a decade and a half ago, when we first began teaching logic by computer. At that time, i t would have been prohibitively expensiw to offer students substantial graphic facilities. ,

Future Progress Needed

Let me close by mentioning t h e e areas in which s~elf-.containccl courses at the university level need richer and better facilities.

First is the important probllem of the processing of' natural language. I t is i n certain ways a bit of a scandal that we still are so awkward in the processing of natural language in the use of computers. The problem is subtle and complicated, but within various limited contexts we are certainly on the verge of making real progress, even if we do not sok7e the full range of processing difficulties.

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Second, we need better and richer theorcm provers and better and richer symbolic calculators. Here we can take a more optimistic view - tile p-oblcm is a much more constrained one than that of processing natural language. i v e can anticipate having rich and powerful software tech- nology available for thc teaching of a wide range of courses in mathw matics and science in the decade ahead, but progress is needed all :h:>

wmc. The work must be donc. I am optimistic that it will be. Third, I mention the psychological pro-blem of haling bettcr nlodel5

o f the student at work proving a theorcm, solving a problem, or writing a coherent and clear essay. Here the software technology is much more primitive but there is reason to bc> hopeful that progress can be made i n ways that will be helpful, et-en if deeper problems of understanding the rele\'ant cogniti\-e qtructurcs, n- i l l eludc un f w some ime to come.

REFERENCES

P. Suppes (Ed.) (1981). Univcrsity-Leucl Computer-Assisted Instruction at SfnnJorcl : 196'8-2980. Stanford, CA : Stanford University, Institute for Mathematwl Studies in the Soclal Sciences.