Kursanalys för Avancerad Funktionell Programmering läsperiod 4 läsåret 2004/2005

Transkript

1 Johan Glimming Nada KTH 2005-aug-31 Kursanalys för Avancerad Funktionell Programmering läsperiod 4 läsåret 2004/2005 Kursdata Momentindelning LAB1, laboration 3/4/5 (2p) TEN1, tentamen 3/4/5 (2p) Kursen genomförd period , april-maj Föreläsningar 28h föreläsningar, 14h laborationer Kursledare Johan Glimming Kurslitteratur B.C. Pierce, Types and Programming Languages, MIT Press, P. Hudak, The Haskell School of Expression: Learning Functional Programming Through Multimedia, Cambridge University Press, Antal studenter 12 Gjort moment LAB1 laboration 10 Gjort moment TEN1 tentamen 7 Prestationsgrad 71% (innan omtenta) Johan Glimming! 31/8/05 18:55 Comment: (7*2 + 10*2) / 12*4

2 Examinationsgrad 58% (flera studenter har valt att göra omtentamen istället i slutet av sommaren, troligen på grund av arbetsbelastning, se nedan) Johan Glimming! 31/8/05 14:06 Comment: 7/12 Mål Kursen syftar till att ge erfarenhet av att använda avancerade koncept inom moderna funktionella språk, t ex parametrisk polymorfism, typklasser, och generisk/polytypisk programmering ge kunskap om metoder för konstruktion av korrekta funktionella program genom härledning av algoritmer från specifikation till en implementation ge grundläggande förståelse för den teoretiska grunden för funktionella språk Sammanfattning Kursen har getts för första gången på KTH. Antalet studenter som läste kursen var relativt lågt. Flera av eleverna presterade väl i mini-projekt och/eller tentamen (höga betyg således). De elever som gjorde hemuppgifterna presterade över lag bäst. Den laborativa delen av kursen resulterade i flera spännande projekt, och många valde att göra frivilliga utökningar. Kursutvärderingen visar att studenterna är nöjda med kursen, även om den uppfattas som svår. Faktiskt innehåll i kursen Kursen har fokuserat på den teoretiska grunden för funktionella språk, dvs typad lambdakalkyl. Detta syftade till att ge en djupare förståelse av funktionella språk, formella metoder för dessa, samt är användningsbart vid analys av andra programmeringsspråk som ofta reduceras till någon variant av lambdakalkyl (t ex objektorienterade språk). Efter en genomgång av lambdakalkylen gick vi vidare till typinferensproblemet och gick igenom Hindley-Milner typsystemet. Detta tjänar till att ge en god förståelse av Haskells typsystem. Efter detta gick vi vidare med mer praktiska tillämpningar, t ex monader och programtransformationer i funktionella språk. Detta förutsatte att studenterna

3 först förstått t ex ekvivalens mellan två program, vilket formaliserades i lambdakalkylen för Haskell-liknande program. Tiden räckte ej till att gå in på generisk programmering även om hemtentamen ger studenterna tillfälle att börja nosa på relaterade frågeställningar. Istället fokuserade kursen denna gång mer på lambdakalkylen (30% av föreläsningarna). Anpassning till andra kurser Förkunskaperna i Haskell varierade. De studenter som hade läst Programmeringsparadigmer bedömer jag har haft bra förkunskaper för kursens programmeringsmoment. Jag tror att det finns god förutsättning för samarbete med kursen teoretisk grund för objekt-orienterad programming. Fortsättningskursen (Semantik för Programmeringsspråk) passar väl ihop med innehållet i denna kursomgång eftersom grunderna i lambdakalkylen diskuterats noggrant. Examination Kursen har examinerats i form av hemtenta tillsammans med ett projekt och slutbetyget utgörs av medelvärdet av de två resulterande betygen (3/4/5). Min uppfattning är att laborationsmomentet fungerat mycket bra. Speciellt några projekt har studenterna utfört mycket väl (typiskt de svårare projekten) Studenterna har själva fått välja sitt mini-projekt i början av kursen, och redan då har jag gett en signal om svårighetsgraden på de olika projekten. Detta har gjort att studenterna om de önskat har kunnat styra in sig mot en betygsambition redan från början. Hemtentamen tycker jag också fungerade bra som examinationsform. Studenterna påtalade t ex att detta gav dem tillfälle att lära sig mer än vad föreläsningarna hade tagit upp (se enkät). Samtidigt har jag haft som princip att studenter som följt kursen och gjort alla hemtal ska ha mycket goda förutsättningar att klara av hemtentamen. Vissa frågor i hemtentan har t ex liknat tidigare hemuppgifter.

4 Kursens belastning på eleverna Mitt intryck är att flera studenter har läst kurser parallellt i högre takt än 1 poäng per vecka. I enkäten anger t ex 2/3 av studenterna att de läste två eller fler andra kurser samtidigt! Detta gjorde troligtvis att det varit svårt för vissa att hinna skicka in t ex hemtal i tid. Som en följd är även examinationsgraden cirka 60 procent. Kanske har även hemtentan uppfattats svår (även om ingen valde Bloody Hard i enkäten denna gång; alla svarade Hard ). Planerade förändringar En möjlighet är att fokusera kursen mindre på lambdakalkyl och typinferens, och desto mer på programkonstruktion, funktionella algoritmer och datastrukturer, samt generisk programmering. Fördelen med denna kurs är att det finns mycket material att välja bland, och varje kursomgång kommer troligen att få sin egen prägel. Min ambition inför nästa kursomgång är att göra hemtentamen mer problemorienterad och kanske minska antalet frågor till förmån för ett fåtal svårare och mer kreativa uppgifter där studenterna uppmuntras i sin nyfikenhet. Några studenter påpekade i enkäten att det hade varit bättre med färre teoretiska föreläsningar i början av kursen så att de kunde komma igång bättre med miniprojekten. Detta kan vara en strategi. En annan är att tillhandahålla ännu tydligare strukturerade projektspecifikationer så att studenterna kan komma igång med programmering redan med sina förkunskaper från t ex Programmeringsparadigm-kursen. Allra helst ser jag att varje mini-projekt innehåller delmoment som matchar vart och ett av kursens olika komponenter och att därmed studenterna kan närma sig projektet redan från början och sedan kontinuerligt i takt med deras inlärning. Det kan dock vara bra med vissa aha -upplevelser som leder till att dom får tänka om och revidera tidigare delmoment.

5 BILAGA: Kursenkät COURSE DESIGN Before you answer this question, consider if you had the required prerequisites. Estimate the level of difficulty of this course. 0% (0 st) Very Easy. 0% (0 st) Easy. 0% (0 st) Average. 89% (8 st) Relatively hard. 11% (1 st) Very hard. Was the course interesting, meningful and/or rewarding? 11% (1 st) Yes, this course was one of the most interesting courses I have taken so far. 56% (5 st) Yes, very. 33% (3 st) Yes. 0% (0 st) Not sure. 0% (0 st) No. 0% (0 st) Entirely uninteresting. The prerequisites for the course were stated in Lecture 1 and includes logic and algorithms, and discrete mathematics. Do you think your own prerequisites were sufficient? 78% (7 st) Yes. 11% (1 st) Not sure. 11% (1 st) No. Since there is no single good enough coursebook for the material of this advanced course, we had to use two textbooks. What do you think about the first coursebook (Pierce, Types and Programming Languages)? 0% (0 st) Outstanding/superb. 44% (4 st) Very good. 11% (1 st) Good. 11% (1 st) Reasonable. 0% (0 st) Not so good. 0% (0 st) Bad. 33% (3 st) Never used it... You have the option of adding a comment (e.g. did you actually use this book, and to what extent did it clarify the material given on-line, in additional recommended textbooks, and in lectures?): I couldn t aford this book. I used mostly articles, but some chapters were helpfull Väldigt bra bok, synd att den kom in ett tag efter kursstart.

6 Similarly, what did you think about the Haskell coursebook by Hudak? 0% (0 st) Very good. 22% (2 st) Good. 22% (2 st) Reasonable. 33% (3 st) Not so good. 0% (0 st) Bad. 11% (1 st) I managed without it. You again have the option of commenting on this textbook (and if you managed without it, how did you manage)?: I dont know if there is some other better in monads but its more oriented in graphics and not so good in other haskell features. Online resources and lectures Didn't read that much but I feelt it wasn't that useful for the course. Since this is a D-level course, a lot of references for additional reading are provided. Many of these references are on-line. Similarly, we used some on-line research papers (mostly tutorials). All in all, do you think the material provided was enough? 67% (6 st) Yes, it allowed for me to find more information about special areas etc. 33% (3 st) Yes, it was ok. 0% (0 st) Not sure. 0% (0 st) No. You have the option of giving an additional comment: Very good resources, links, papers etc. Did you actually use the proposed reference literature, the links to additional resources, etc? 78% (7 st) Yes. 0% (0 st) Don't remember... 22% (2 st) No. You have the option of giving an additional comment: Good help on monads Very good resources, links, papers etc. LECTURES Give an estimate on the number of lectures you attended? 11% (1 st) Less than 20%. 22% (2 st) 20-40%.

7 11% (1 st) 40-60%. 22% (2 st) 60-80%. 33% (3 st) More than 80%. Did you come prepared to the lectures (i.e. did you read the suggested material before you went to each lecture)? 0% (0 st) Yes, of course. 22% (2 st) Frequently. 33% (3 st) Sometimes. 22% (2 st) Rarely. 22% (2 st) Never! If not, why not? I didn't have the book (and I don't think I've ever read anything in advance.) Not enough time; if needed tried to read afterwards. Kom lite efter med teorin i början vilket störde. Was the pace/speed of each lecture adequate? 56% (5 st) Too fast. 0% (0 st) Too slow. 44% (4 st) Just about the right pace. What is your overall opinion about the lectures? 0% (0 st) Very good and highly enjoyable! 33% (3 st) Good. 22% (2 st) Average. 33% (3 st) Not so good. 0% (0 st) Completely worthless. 11% (1 st) Could not attend. Give motivation to your answer by means of constructive criticism to make room for improvements for next year's course: Perhaps it is better to concentrate on a few important things, work on examples in the blackboard,...etc. Sometimes I needed more time to assimilate concepts and not jump to others. but on the other hand i havent work at home before going to the lectures. Far too much time was spent on examination of the homework. Lectures based purely on slides aren't very easy to follow. Personaly i thing lectures are just an intro, to help u with stuggling it on your own afterwards. The lectures fullfilled my expectations, but still i believe this should be a 2period course, so that the teacher can take it more slowely, and cover more depths and breadth.

8 Some stuff needs more explanation first time they are encountered (Monads). Problemet som jag ser det är engelskan. Föreläsaren talar en tekniskt mycket bra engelska, men har inte det riktiga flytet som personer som har engelska som modersmål. Den mycket varierande kvalitén på engelskan hos kursdeltagarna har en negativ inverkan, då föreläsningarna var relativt interaktiva. Föreläsningsanteckningarna var mycket bra. Did the teacher answer and encourage your questions (during lectures)? 89% (8 st) Very much so. 11% (1 st) To some degree. 0% (0 st) Not really. What could the teacher have done to improve the interactive form of the teaching in this course? Do you prefer interaction during lectures or should the lecturer just talk and you listen? I like interaction. There wasn't that much interaction but i think lectures are best that way. As long as the teacher covers the course material, interactions can be held to a minimum. Interactions is important, but within some limits, so that the flow of the course would not be disturbed. I thing, the practise "lisend first, and ask questions latter" is the best. More or less thats what has been done The form of the lectures was good. MINI-PROJECTS, HOMEWORK EXERCISES AND BONUS SYSTEM Generally, did you attempt to solve the homework (even if you did not submit anything)? 78% (7 st) Yes. 22% (2 st) No. In the event you did not hand in homework, what are the main reasons for this? What could have made you actually submit homework? lack of time. I couldn't understand it. It was too hard and I didn't have enough time. basically i am not fun of deadlines and pressure, but the exersices were interesting, i took my time to thing about them

9 Redovisar inte gärna på tavlan om jag inte är supersäker på att jag har ett helt korrekt svar. Give your opinion on the difficulty of the homework (with exception for one question in homework 4 which could not really be solved since it was a typo in SOE)? 67% (6 st) Homework difficulty is consistent with the inherent difficulty of the course. 0% (0 st) Homework was easy, which was good for my learning! 0% (0 st) Homework was too easy. 11% (1 st) Neither applies, see my comments. 22% (2 st) Homework was too hard; I think it goes beyond the requirements for examination. Comments (e.g. how should the homework exercises change for next year, if at all, and was the homework useful for your motivation and learning experience, and also changes in the bonus system etc?): I think, at least the homework i have work on, that it was good to consolidate the concepts of the course. Homeworks were very helpful and help a lot to solve and exam. You had to put down way to much effort for that small reward. I would have tried harder if the homework could have been submitted in text instead of presentations. I thing it would be good for the homework and the lectures to be available from the beggining of the course. I think next year it wont be hard, since now everything is double checked Estimate the difficulty of your project? 0% (0 st) Too hard, we barely made it. 78% (7 st) Hard, but doable. 22% (2 st) As expected. 0% (0 st) Quite easy. 0% (0 st) Very easy. 0% (0 st) Trivial! Would you prefer a different form for the mini-projects (e.g. individually, larger groups, fewer projects to choose from, more freedom, etc)? If so, please explain it here: i think is o,k, smaller projects that starts later in the course so that you have some knowledge of how to do things. More freedom OR more detailed explanations of the project parts. my project is fun. i thing the number of project and the size of the team are chosen good, in accordence to the number of students attending the course

10 How much time did you (roughly) spend on the mini-project (just your own portion of the work, not including other group members)? 0% (0 st) Less than 5 hours. 11% (1 st) 5-10 hours. 0% (0 st) hours. 22% (2 st) hours. 33% (3 st) hours. 11% (1 st) hours. 11% (1 st) More than 50 hours. Comments: i didn't finish it yet, probably will take more. I didn't really use a timmer to count the hours, but the project is really demandying in self study, couse i have to grasp the basics of Martin-Lof type theory, which is not a simple toy. I dont know how many hours eller mer. Was the teacher engaged in your mini-project and did he answer your questions and helped you whenever you got problems, etc? 22% (2 st) Super good. 44% (4 st) Good. 33% (3 st) Enough. 0% (0 st) Not enough. 0% (0 st) Little. Expand on it: when i have had a problem and ask for help i have had that help.i had help to choose and even change the project as well. we didn't need help. I didn't really need much help from the teacher on this project, couse my member has good theoretical basis in Martin-Lof. Haskell like hints, though, were very helpfull We got all the help we needed. Läraren var mycket bra och engagerad i projektet. Tog sig tid att svara på frågor och föreslå relativt material. Var snabb att svara på mailade frågor vilket alltid är mycket uppskattat. How did the teamwork sort out for you? Did all team members contribute evenly to the final outcome of the project?

11 0% (0 st) Absolutely not. 11% (1 st) Not really. 11% (1 st) Somewhat. 33% (3 st) Very much so. 44% (4 st) Totally so. How could the teacher have helped you to sort it out (if applicable), and what do you in general propose to improve the situation with teamwork next year? Í don't really think that it should be improved - Johan is very helpful to sort out the problem with team members. There isn't much the teacher can do. My partner is ok, eventhough i didnt know the guy before, but we could colaborate. FINAL EXAMINATION Estimate the difficulty of the take-home examination? 0% (0 st) Bloody hard. 78% (7 st) Hard. 0% (0 st) Average/what I would expect. 0% (0 st) Easy. 0% (0 st) Man, this is too easy! ;-) 22% (2 st) Did not take the exam. Additional comments: Since it just started it's hard to answer. There is a lot of work with the take home exam Good to have a take-home exam instead of ordinary exam ; it enabled you to learn about things that hadn't been in the lectures (but were in the questions). Is 14 days too generous for this sort of examination? (The idea was to allow for more creative problems, such that the examination itself is a learning experience!) 56% (5 st) No, it should be 14 days. 11% (1 st) Don't know. 22% (2 st) No, should be less. 11% (1 st) It should be more... GENERAL QUESTIONS How many other courses did you take in parallel with this course (i.e. in this second half of the spring)? 0% (0 st) Zero (just this one). 33% (3 st) One.

12 33% (3 st) Two. 33% (3 st) Three. 0% (0 st) Four. 0% (0 st) Five or more. How demanding in terms of your total study time (full time study during 8 weeks for 4 credits means formally 4 hours per workday)? 0% (0 st) On average less than 1 hour per workday (5h/week). 0% (0 st) Between 1h/day (5h/week) and 2h (10 h/week). 56% (5 st) Between 2h/day (10h/week) and 4h (20h/week). 33% (3 st) Between 4h/day (20h/week) and 5h (25h/week). 11% (1 st) Between 5h/day (20h/week) and 7h (35h/week). 0% (0 st) More than 7h/day (35h/week). The course can give you 4 points (2 for lab and 2 for exam). What is your opinion about the number of credits rewarded for your work? 67% (6 st) 4 credits is suitable. 33% (3 st) Should be 5 credits. 0% (0 st) Should be 6 credits. 0% (0 st) 4 credits are too much! Here we allow for you final suggestions for improvements of this course. What was bad? What was good? The difficulty-slope should be flattened. Now we started with one lecture learning some Haskell, then we quickly moved on to much more advanced topics. For those of us, not familiar with functional programming at all, more time should be spend on the basic concepts, writing programs using a functional language i.e. It was good and interesting. Needs more iterations to converge to optimal solution :) More practical (at least from the begining) so that you can get started and produce functional code. maybe some coding homework (labs) before/instead of the mini projects. i thing the subject is so exciting, a bit more time would be great. I also belive in learning by example. So would like to see big peaces of good programming examples fully worked out in the class. of course due to the time constraints it was impossible. But maybe some links would be great. En mycket intressant kurs med en engagerad lärare. Formatet på föreläsningarna behöver, enligt min åsikt, ändras något. Annars inget att klaga på.