Experiences with a new introductory informatics course



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Anatomy of Computer Systems

Experiences with a new introductory informatics course

Hanno Wupper

Computing Science Institute

Faculty of Science

University of Nijmegen

Toernooiveld 1, 6525 ED Nijmegen, NL

Hanno.Wupper@cs.kun.nl

Abstract


Is it possible to convey, in no more than five days, some useful understanding of ICT and to elucidate what informatics has to do with all this?

A compact course in five days explores the phenomena of ICT top-down, from the level of Internet applications to the realisation of hardware by logical circuits, and illustrates the role of the science informatics with speaking examples. The course aims at insight in possibilities, limitations, and fundamental principles rather than at technical skills.

Goals and architecture of the course are established; a summary of its contents is given; the teaching method is sketched; and the experiences made when it first was given are summarised. The reactions of the participants can be found in an appendix.

Acknowledgements


Tom van Weert was the first to challenge the author to design a course that investigates computer systems starting from the surface and working downwards much like it is done in dissecting practicals in human anatomy.

A course covering much more than described here was prepared and given in 1998 by the author together with Erik Barendsen. The present paper, in which Erik regrettably could not participate, describes only selected aspects. It can also be read as the description of a hypothetical “light” version of that course.


Summary in Dutch


In 1998 werd in Nijmegen een nieuwe introductiecursus informatica ontwikkeld en voor het eerst gehouden. Deze blokcursus van vijf volle dagen vormt thans in Nijmegen het begin van de studie informatica, in de eerste collegeweek van het eerste jaar. Doel is begrip, inzicht en overzicht over de fenomenen uit de ICT van toepassingen op het hoogste niveau tot en met de realisatie op het niveau van logische schakelingen alsmede een eerste verkenning van de rol van de wetenschap informatica.

Deze cursus breekt met twee tradities: het gaat om inzicht en niet om vaardigheden in het gebruik van specifieke huidige systemen, en computersystemen worden ‘top-down’, d.w.z. van buiten naar binnen ontleed en niet ‘bottom-up’ opgebouwd.

De cursus leent zich ook voor andere doelgroepen die willen leren zich verantwoord te oriënteren op het verwarrende gebied va de ICT, die kwaliteit van ICT-toepassingen willen kunnen beoordelen, over de maatschappelijke consequenties nadenken en begrijpen hoe en waarom computers kunnen functioneren en wat hun beperkingen zijn. Te denken valt aan leidinggevenden in politiek en bedrijfsleven en aan docenten en wetenschappers juist buiten het vakgebied informatica die op academisch niveau willen kunnen meedenken, zonder daarbij te verdrinken in technische details. De cursus is niet bedoeld voor werknemers die zo snel mogelijk technische vaardigheden met bijvoorbeeld tekstverwerkers of informatiesystemen moeten verwerven.

Voor de Nijmeegse informaticastudenten is de cursus bedoeld als eerste oriëntatie op het hele vakgebied. Vroeger bestond de basisopleiding alleen uit zorgvuldig in elkaar gezette, over meerdere semesters lopende cursussen in de vakken programmeren, architectuur, wiskunde enz. volgens de klassieke ‘bottom-up’-opbouw. Wat de verschillende stromen met elkaar te maken hadden en waartoe het allemaal moest leiden – daar moesten de studenten zelf maar met verloop van tijd achter zien te komen. Er is weinig mis met zo’n klassieke curriculumopbouw, behalve dat veel studenten gefrustreerd raken en sommigen te vroeg met hun studie stoppen. Wie informatica wil studeren uit fascinatie voor het internet of toepassingen als Photoshop® zal zijn belangstelling alleen dan op onderwerpen als logische schakelingen, verzamelingenleer of reguliere expressies kunnen richten als enigszins duidelijk is waar zo iets droogs allemaal toe dient. Wie zijn studie met succes afrondt, weet zijn solide theoretisch fundament met terugwerkende kracht te waarderen, maar te veel begaafde studenten geven thans hun studie op omdat ze door de in hun ogen saaie inhoud teleurgesteld worden, en wie niet opgeeft ervaart toch vaak sommige vakken in het begin als overbodig en frustrerend. We hopen dat de studie minder ontmoedigend ervaren wordt als men van begin af het doel helder ziet en kan plaatsen waar de diverse onderwerpen allemaal goed voor zijn en wat ze met elkaar te maken hebben.


De vorm van de cursus wordt bepaald door de doelen, de inhoud en de onderwijsmethode.
De methode wordt bepaald door twee beginselen: laat de studenten een complex computernetwerk verkennen door het van buiten naar binnen te ontleden en stimuleer ze de fenomenen en beginselen die de revue passeren zelf te ontdekken en te begrijpen zonder de weg kwijt te raken door allerlei technische details. Hiertoe moeten de studenten zo snel mogelijk leren dat men de fenomenen op een bepaald niveau kan begrijpen onder de voorwaarde dat men bepaalde aannames over het onderliggende niveau pas later verifiëert. De docenten moeten daartoe zelf een goed beeld hebben van de gelaagde opbouw, en ze moeten voortdurend in de gaten houden dat vragen omtrent het onderliggende niveau scherp geformuleerd maar niet beantwoord worden voordat men op een latere dag aan dat niveau toe is. De docenten moeten niet de rol spelen van experts die antwoorden geven, maar van wijze leraren die de studenten helpen, zelf de relevante vragen te ontdekken.

Introduction


The author developed in co-operation with Erik Barendsen an introductory course on informatics, which was given for the first time in the summer of 1998. This course, consisting of five full days, now forms the very beginning of the undergraduate study of informatics in Nijmegen. Its goal is understanding, insight, and overview with respect to the phenomena of information and communication technology, from the highest level down to the realisation by logical circuits, as well as a first exploration of the role of informatics as a science.

This new course breaks with two traditions: It focuses on insight and overview rather than on practical skills, and it anatomises computer systems ‘top-down’, viz. from the surface at the level of internet applications downwards to electronic circuits rather than constructing them ‘bottom-up’ from their basics.

The present paper, to which Erik regrettably could not contribute, only describes about half of the course’s philosophy and content. A “light” version of our course, as it is covered by the present paper, consisting of five lessons of half a day each, could be interesting also for other audiences than beginning students of informatics. It might be helpful to everyone who, being not an ICT expert, would like to get a better understanding of that confusing area. It could help politicians, managers, teachers, and scientists outside informatics to be able to recognise quality (or the absence of it) in ICT products, to form an opinion about societal consequences of ICT, or simply to understand why computers can function at all and what their limitations are without being drowned in technical details.

The course is not, however, meant for employees who have to learn technical skills in the usage of particular computer applications as quickly as possible.

For Nijmegen informatics students the course is to provide a first orientation on the entire discipline. Until it had been developed, the undergraduate curriculum started with a number of carefully designed parallel courses, each of which stretched over two or more semesters: programming, computer architecture, theory, and mathematics. These courses followed the classical “bottom-up” approach from the simple basic concepts to the complex ones, like it has been customary in mathematics for many years.

The hardware course first investigated Boolean algebra and logic circuits, then the construction of programmable processors, and ended studying operating systems and networks. The programming course started with simple imperative programming in a carefully chosen didactic programming language; it introduced complex programming language concepts only after half a year’s experience with simple ones. Theory set off from finite automata and regular languages and carefully worked towards the Turing machine as coronation of all efforts.

This is the approved way to build a solid pyramid of knowledge, and there is nothing wrong with it except that too many students tend to get frustrated. If one is fascinated by the Internet, robots, video games, or applications like Photoshop®, exercises with transistors and regular languages can be frustrating unless it is apparent what they are good for. Those who bring their study to a good end will appreciate—afterwards—that they were given a solid basis. But too many give up before they can ever see why they have to learn these stuffy subjects. And many of those who do not give up encounter the core courses of their curriculum as frustrating obstacles.

There is much to be said for bottom-up presentation of knowledge—as long as students know what all those subjects are good for and what it all will lead to. If they don’t—why should they care about set theory, finite automata, a program that computes the factorial, and Boolean algebra in the first weeks? These subjects, boring to those not attracted by the beauty of mathematics, seem not even to have anything to do with each other—let alone with the fascination of the Internet. How can you ever be fascinated by the addressing modes of the instruction set of a certain processor if you have not experienced the usefulness of complex data types? How can you lay the link between hardware and software if the compilation and linking of your programming exercises is hidden by a didactic programming environment, until you see the first compiler of your academic life in an advanced course on compiler construction?

The authors’ hypothesis was that a small addition to the curriculum might prevent many problems: a short, compact introductory course at the very beginning that explores the pyramid of knowledge upside-down.

This approach is not uncommon in other academic disciplines. For centuries students of medicine have started by dissecting a corpse, outside in. From the complex but well-known to the small and unknown. Before they understand about physiology, orthopedy, or which specialisation ever, they get the chance to learn, in a relatively short time, how the complete human body is organised, from what you see at the surface down to the level of tissue. They learn to get oriented in the main subject of the discipline they want to study.

At many universities the classical study of natural science starts with a big and impressive “circus”, where as many as possible of the fascinating phenomena of physics are actually demonstrated in the lecture hall. Students see the richness and fascination as they will hardly ever see it later.

The question is: can something similar be done for informatics? An introductory course that demonstrates the fascinating phenomena that are studied and (other than in the case of medicine) created by informatics—in all their richness, starting from the complex and well-known surface, gradually going deeper to the small and simple, but unknown.

To get some evidence, a one-week course “Introduction to Informatics” was developed and given. A more speaking title would have been “Anatomy of computer systems”, but the Department of Informatics considered that too revolutionary.

The full course, as it was actually given first in 1998, had to meet extra goals not covered by this paper. It had to make another course superfluous, which tried to prepare students for the pitfalls of academic learning and to teach them practical skills in using the department’s computer systems. These aspects are not covered by the present paper, which attempts to explain the philosophy and architecture of the “light” version of the course and to show what has been achieved during the first time it was given: how did it go, what have the students learned, did they like it?

After a brief statement of the goals and methods we present a chronicle of what actually happened from day to day.

Although we hope to inspire and encourage lecturers to follow a similar concept in teaching, this report is not meant to be a didactical text on how to plan and give such courses. In a later publication we shall explain in detail how we planned and prepared it.





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