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Here are PDFs of the slides of the lectures so far: [[attachment:SearchEnginesWS0910/lecture-1.pdf|Lecture 1]], [[attachment:SearchEnginesWS0910/lecture-2.pdf|Lecture 2]]. | Here are PDFs of the slides of the lectures so far: [[attachment:SearchEnginesWS0910/lecture-1.pdf|Lecture 1]], [[attachment:SearchEnginesWS0910/lecture-2.pdf|Lecture 2]], [[attachment:SearchEnginesWS0910/lecture-3.pdf|Lecture 3]], [[attachment:SearchEnginesWS0910/lecture-4.pdf|Lecture 4]], [[attachment:SearchEnginesWS0910/lecture-5.pdf|Lecture 5]], [[attachment:SearchEnginesWS0910/lecture-6.pdf|Lecture 6]], [[attachment:SearchEnginesWS0910/lecture-7.pdf|Lecture 7]], [[attachment:SearchEnginesWS0910/lecture-8.pdf|Lecture 8]]. |
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Here are PDFs of the exercise sheets so far: [[attachment:SearchEnginesWS0910/exercise-1.pdf|Exercise Sheet 1]], [[attachment:SearchEnginesWS0910/exercise-2.pdf|Exercise Sheet 2]]. | Here are .lpd files of the recordings of the lectures so far (except Lecture 2, where we had problems with the microphone): [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-1.lpd|Recording Lecture 1]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-3.lpd|Recording Lecture 3]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-4.lpd|Recording Lecture 4]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-5.lpd|Recording Lecture 5 (no audio)]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-6.lpd|Recording Lecture 6 (with audio for a change)]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-7.avi|Recording Lecture 7 (AVI)]], [[http://vulcano.informatik.uni-freiburg.de/lecturnity/lecture-8.avi|Recording Lecture 8 (AVI)]]. |
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Here are your solutions and comments on the previous exercise sheets: [[SearchEnginesWS0910/ExerciseSheet1|Exercise Sheet 1]]. | Here are PDFs of the exercise sheets so far: [[attachment:SearchEnginesWS0910/exercise-1.pdf|Exercise Sheet 1]], [[attachment:SearchEnginesWS0910/exercise-2.pdf|Exercise Sheet 2]], [[attachment:SearchEnginesWS0910/exercise-3.pdf|Exercise Sheet 3]], [[attachment:SearchEnginesWS0910/exercise-4.pdf|Exercise Sheet 4]], [[attachment:SearchEnginesWS0910/exercise-5.pdf|Exercise Sheet 5]], [[attachment:SearchEnginesWS0910/exercise-6.pdf|Exercise Sheet 6]], [[attachment:SearchEnginesWS0910/exercise-7.pdf|Exercise Sheet 7]], [[attachment:SearchEnginesWS0910/exercise-8.pdf|Exercise Sheet 8]]. Here are your solutions and comments on the previous exercise sheets: [[SearchEnginesWS0910/ExerciseSheet1|Solutions and Comments 1]], [[SearchEnginesWS0910/ExerciseSheet2|Solutions and Comments 2]], [[SearchEnginesWS0910/ExerciseSheet3|Solutions and Comments 3]], [[SearchEnginesWS0910/ExerciseSheet4|Solutions and Comments 4]], [[SearchEnginesWS0910/ExerciseSheet5|Solutions and Comments 5]], [[SearchEnginesWS0910/ExerciseSheet6|Solutions and Comments 6]], [[SearchEnginesWS0910/ExerciseSheet7|Solutions and Comments 7]]. = Exercise Sheet 8 = The recordings of all lectures are now available, see above. Lecture 2 is missing because we had technical problems there. To play the Lecturnity recordings (.lpd files) you need the [[http://www.lecturnity.de/de/download/lecturnity-player|Lecturnity Player, which you can download here]]. I put the Camtasia recordings as .avi files, which you can play with any ordinary video player; I would recommend [[http://www.videolan.org/vlc|VLC]]. |
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= Exercise Sheet 2 = Details about our three servers, as required for Exercise 4, will be given here by the end of Friday. [[SearchEnginesWS0910/ExerciseSheet2|Here you can upload your solutions for Exercise Sheet 2]]. |
[[SearchEnginesWS0910/ExerciseSheet8|Here you can upload your solutions for Exercise Sheet 8]]. |
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Hi Björn + all: For Exercise 4 from Exercise Sheet 1 you had to write code that is at least able to process 2-word queries. If your code can indeed only handle 2-word queries and not an arbitrary number of query words, that is also fine for this exercise, you won't get less points because of that. Your second question is also very valid. You should put the various functionalities into modules / classes of their own, so that you can easily combine them for the three different binaries required for Exercises 1 - 3. Each of your three programs will then be quite short, just putting together the right things. I should have added it to my list of evil coding NoNos: never ever duplicate code, but instead put it in a class / module of its own. I hope this answers your questions, if not please ask again. Sorry for the late answer, but I was super busy until now, hardly had time to breathe. '''Hannah 30Oct09 19:08''' | To all: Exercise 3 is certainly the hardest on this sheet. Although again nobody has asked for a hint so far, here is one: You have to prove that ED(x, y) = EDm(x, y), where ED is the normal edit distance, and EDm is the edit distance where the sequence of transformations must be monotone, as defined in the lecture and on the sheet. ED(x, y) <= EDm(x, y) is trivial since every monotone transformation sequence is also a normal transformation sequence. To prove EDm(x, y) <= ED(x, y), the natural way is again to use induction over |x| + |y|, as done in the lecture for my proof of Lemma 2 (which didn't quite work out, but for other reasons). If you need more hints, ask. '''Hannah 14Dec09 14:46''' |
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Hi Björn, I don't understand why/how you would need that a transformation "knows" its position. I also don't see that there is any big formalism involved in what a transformation is. A transformation is one of insert / delete / replace, and it occurs at a particular position of the current string. That is a transformation, no more no less. '''Hannah 14Dec09 14:42''' | |
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I have a question concerning exercise 2. There was no concrete task to produce "query processing code" on ex sheet 1. Are there any requirements that have to be fulfilled? Should it be able to handle two word queries? n-word queries? Additionally there is something else I want to ask: I think it surely isn't bad practice to write a more generic webserver and use it for exercises 1-3. Apart from that it says "change your code" some times in the exercises. How should your submission behave w.r.t. the exercises? Different src files / executables for each exercise? One program that solve each exercises depending on startup parameters? Anything else? '''Björn 30ct09 2:25pm''' | One question on exercise 3: Do we have to assume that each transformation is of a certain form (i.e. insert at i'th character of current word, where it matters how many deletes/inserts have been done previously)? Or can we assume that a transformation somehow "knows" its position? If we have to deal with it in an abstract way, should we create our own way of describing a transformation or is there a formalism we all should use. '''Björn 13:31''' |
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I now reorganized the page. Old stuff went to separate pages (links above). The idea is that the front page is always for the current lecture / exercises. The problem with your exercise page should be solved now, Ivo. '''Hannah 30ct09 00:05am''' | Here is another bonus point system: http://www.informatik.uni-freiburg.de:8081/swt/teaching/winter-term-2009/informatik-iii-theoretische-informatik. Additionally I would like to add that most of these bonus point systems have exercises which are far less work. '''Björn''' |
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Having problems to access my exercise page after loging in - IvoChichkovExercises, '''Ivo 29Oct 22:56pm''' | In some other lectures the points from the sheets are used to increase the grade from the exam. If one got 50% then she/he got 0.3 grade better, 80% for 0.6 better, but min. 4.0 in exam. I.e. 83% of the exercise points and 2.3 in exam = 1.7 final grade. Data Mining & Machine Learning used a more complex scheme, there was theoretical sheets and practical sheets using Weka (the slides should be on electures server). '''Markus 14Dec09 9:23''' |
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Sorry to bother you. I added the Link to exercise sheet 2 with the linked pdf. Needed this to find the sheet as fast as possible. '''Marius 29Oct 10:04 p.m.''' | Many exercise sheets contained two tasks and for each task we could get 1 point. That means that we could got 2 or even 3 points per sheet. The exercises were optional, but because of the bonus points most students did the exercises. There was another reason to do the exercises. In this lecture the exam was very similar to the exercise sheet tasks, so we had two considerable advantages. In two other lectures we had to achieve 30 and 50% of the exercise points to participate at the exam. '''Manuela 14Dec09 00:57''' |
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Is there a webpage for exercise sheet 2 somewhere? '''Johannes 29Oct 07:45 pm''' | Now that I think about it, there were points for solving exercises in exercise-class. Also, there were more than 15 points achievable over the semester, but max. 15 were credited in the exam. '''alex 13Dec09 23:57''' In that lecture we could reach max. 15 bonus points for the exercises. Each exercise sheet scored one point + one extra point for specially good/clever solutions. I don't think there was a constraint on admission to the exam. There might have been points for solving exercises in the exercise-class, but I'm not sure about that. (--> already one year ago) '''alex 13Dec09 23:48''' Thanks for the link, Alex, can you please explain the thing with the "bonus point of the exercise"? Is it that there were 15 bonus points to reach in the exercises? How many tasks in the exercises got bonus points and how many didn't? And the non-bonus tasks than only counted for admission to the exam? '''Hannah 13Dec09 23:36''' I quite liked this scheme, although it does not put that much weight on the exercises: http://cone.informatik.uni-freiburg.de/teaching/vorlesung/algorithmentheorie-w08/exam.html '''alex 13Dec09 23:17''' Can someone please post the details of one of the existing bonus systems here? (Something like: for xyz % of the exercises, you can improve your exam mark by abc.) Or the links to a course site where these details are given. Thanks! '''Hannah 13Dec09 23:09''' To Mirko + all: Yes, it's d, I don't know how I've missed this one. '''Marjan 12Dec09 13:16''' About Exercise 1: in the second part, is it really delta? shouldn't it be d? '''Mirko 12Dec09, 12:43''' |
Welcome to the Wiki page of the course Search Engines, WS 2009 / 2010. Lecturer: Hannah Bast. Tutorials: Marjan Celikik. Course web page: click here.
Here are PDFs of the slides of the lectures so far: Lecture 1, Lecture 2, Lecture 3, Lecture 4, Lecture 5, Lecture 6, Lecture 7, Lecture 8.
Here are .lpd files of the recordings of the lectures so far (except Lecture 2, where we had problems with the microphone): Recording Lecture 1, Recording Lecture 3, Recording Lecture 4, Recording Lecture 5 (no audio), Recording Lecture 6 (with audio for a change), Recording Lecture 7 (AVI), Recording Lecture 8 (AVI).
Here are PDFs of the exercise sheets so far: Exercise Sheet 1, Exercise Sheet 2, Exercise Sheet 3, Exercise Sheet 4, Exercise Sheet 5, Exercise Sheet 6, Exercise Sheet 7, Exercise Sheet 8.
Here are your solutions and comments on the previous exercise sheets: Solutions and Comments 1, Solutions and Comments 2, Solutions and Comments 3, Solutions and Comments 4, Solutions and Comments 5, Solutions and Comments 6, Solutions and Comments 7.
Exercise Sheet 8
The recordings of all lectures are now available, see above. Lecture 2 is missing because we had technical problems there. To play the Lecturnity recordings (.lpd files) you need the Lecturnity Player, which you can download here. I put the Camtasia recordings as .avi files, which you can play with any ordinary video player; I would recommend VLC.
Here are the rules for the exercises as explained in Lecture 2.
Here you can upload your solutions for Exercise Sheet 8.
Questions or comments below this line, most recent on top please
To all: Exercise 3 is certainly the hardest on this sheet. Although again nobody has asked for a hint so far, here is one: You have to prove that ED(x, y) = EDm(x, y), where ED is the normal edit distance, and EDm is the edit distance where the sequence of transformations must be monotone, as defined in the lecture and on the sheet. ED(x, y) <= EDm(x, y) is trivial since every monotone transformation sequence is also a normal transformation sequence. To prove EDm(x, y) <= ED(x, y), the natural way is again to use induction over |x| + |y|, as done in the lecture for my proof of Lemma 2 (which didn't quite work out, but for other reasons). If you need more hints, ask. Hannah 14Dec09 14:46
Hi Björn, I don't understand why/how you would need that a transformation "knows" its position. I also don't see that there is any big formalism involved in what a transformation is. A transformation is one of insert / delete / replace, and it occurs at a particular position of the current string. That is a transformation, no more no less. Hannah 14Dec09 14:42
One question on exercise 3: Do we have to assume that each transformation is of a certain form (i.e. insert at i'th character of current word, where it matters how many deletes/inserts have been done previously)? Or can we assume that a transformation somehow "knows" its position? If we have to deal with it in an abstract way, should we create our own way of describing a transformation or is there a formalism we all should use. Björn 13:31
Here is another bonus point system: http://www.informatik.uni-freiburg.de:8081/swt/teaching/winter-term-2009/informatik-iii-theoretische-informatik. Additionally I would like to add that most of these bonus point systems have exercises which are far less work. Björn
In some other lectures the points from the sheets are used to increase the grade from the exam. If one got 50% then she/he got 0.3 grade better, 80% for 0.6 better, but min. 4.0 in exam. I.e. 83% of the exercise points and 2.3 in exam = 1.7 final grade. Data Mining & Machine Learning used a more complex scheme, there was theoretical sheets and practical sheets using Weka (the slides should be on electures server). Markus 14Dec09 9:23
Many exercise sheets contained two tasks and for each task we could get 1 point. That means that we could got 2 or even 3 points per sheet. The exercises were optional, but because of the bonus points most students did the exercises. There was another reason to do the exercises. In this lecture the exam was very similar to the exercise sheet tasks, so we had two considerable advantages. In two other lectures we had to achieve 30 and 50% of the exercise points to participate at the exam. Manuela 14Dec09 00:57
Now that I think about it, there were points for solving exercises in exercise-class. Also, there were more than 15 points achievable over the semester, but max. 15 were credited in the exam. alex 13Dec09 23:57
In that lecture we could reach max. 15 bonus points for the exercises. Each exercise sheet scored one point + one extra point for specially good/clever solutions. I don't think there was a constraint on admission to the exam. There might have been points for solving exercises in the exercise-class, but I'm not sure about that. (--> already one year ago) alex 13Dec09 23:48
Thanks for the link, Alex, can you please explain the thing with the "bonus point of the exercise"? Is it that there were 15 bonus points to reach in the exercises? How many tasks in the exercises got bonus points and how many didn't? And the non-bonus tasks than only counted for admission to the exam? Hannah 13Dec09 23:36
I quite liked this scheme, although it does not put that much weight on the exercises: http://cone.informatik.uni-freiburg.de/teaching/vorlesung/algorithmentheorie-w08/exam.html alex 13Dec09 23:17
Can someone please post the details of one of the existing bonus systems here? (Something like: for xyz % of the exercises, you can improve your exam mark by abc.) Or the links to a course site where these details are given. Thanks! Hannah 13Dec09 23:09
To Mirko + all: Yes, it's d, I don't know how I've missed this one. Marjan 12Dec09 13:16
About Exercise 1: in the second part, is it really delta? shouldn't it be d? Mirko 12Dec09, 12:43