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Algorithms by Jeff Erickson

jeffe.cs.illinois.edu

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Re: Algorithms by Jeff Erickson

#121

Post by mcguire »

chasd00 wrote: post #104
skrtskrt wrote: post #100

Earlier quoted context omitted.

In college, cheating on the homeworks was quite literally the only way to get all the work for 4 engineering classes done on time. We still learned it all for exams, and received our exam grades accordingly, which are generally >60% of the full grade for the class. But we were putting in 80+ hours a week on engineering classes and it simply wasn't enough for the obscene amount of work professors assigned. Students cr…

I remember two breakdowns while going through Computer Science and Engineering at UTA ( far from a top-tier school, we liked to call it "UT Almost" ) in the late 90s 1. a student in physics broke down sobbing during the final, like uncontrolled wailing. The TA helped her get up and walk out 2. in the discreet structures course a student got up, walked to the front of the room in tears, tore up their final in front of…

I once met an engineering statistics professor under social circumstances. Said professor proceeded to brag about never having a student get an A on his final, along with other similar comments. Later, I took a class from a history instructor who started the first class by going around the room mocking the students individually. (I dropped that sucker so damn fast...)

Some teachers specifically not to teach, but to take power trips over students. They are simply bad. Others are there because it's a paycheck; they're not very good. Some others are confused and loopy. They're not great.

But most of the university and college teachers I've met were interested in teaching students---they're typically teaching something related to the field they've spent their lives on, right? Most were middling good, some were spectacular.

Re: Algorithms by Jeff Erickson

#122

Post by mcguire »

dkfjs wrote: post #49

Not proving solutions to textbooks seems to be a common theme in mathematics and theoretical computer science. It makes it difficult for those outside of the traditional classroom to learn the material. Instead textbook writers seem to have this adversarial approach against readers, thinking they’ll “cheat themselves” if they look up solutions or attempt to verify their work. Experts make mistakes, beginners would pr…

Is that Computer Concrete Roman?!

I guess I'll have to go through this one.

Re: Algorithms by Jeff Erickson

#123

Post by carapace »

aspaceman wrote: post #38
codeisawesome wrote: post #11

Earlier quoted context omitted.

IMO it’s a major waste of time to go through a book if I can’t check my solutions and be satisfied that I understood everything the instructor intended to from the problem. I won’t be investing the time into this book. Algorithms by Sedgwick instead has (third party) Solutions online.

You can still get value from a book that doesn’t give you all the answers. You can even get more value. Christ the answers have been all solved in papers, in literature, it’s all out there in small baby words what to do. But the whole damn point of math is learning to do it on your own. It’s like bitching that an art textbook doesn’t include draw by numbers in the back pages. “I just want to know I’m doing it right“…

Yes. A lot of textbook writers take the time to structure the exercises so that working them out yourself guides you to a much deeper knowledge and appreciation.

One day, out in the real world, you will be faced with problems for which there is no solution ready to go. A good education prepares you for that challenge.

Re: Algorithms by Jeff Erickson

#124

Post by tehjoker »

musingsole wrote: post #107
unishark wrote: post #106

Earlier quoted context omitted.

I don't know what you mean by stealing. In college you are generally supposed to devote twice as many hours outside of class as in class. It's probably stated in your student handbook. That is why 12 to 16 credit hours is called "full time". In a problem-solving discipline the best way to spend that study time is solving problems. As a bonus you can get personalized feedback when it is graded.

I'm going to call that stockholm syndrome. Many people throw around the idea of spend twice as much time in class as out. That's a fine idea for some, but many don't need it. Forcing a student to fill out problems to satisfy the instructor's concept of enough time spent is completely tangential to purpose of an education. There isn't a requirement for the amount of time a MMA fighter spends in the gym. They set their…

In my college (back in the day) they said an A student would spend 4 hours for every 1 hour. For a 15 credit student, that meant 60 hr work weeks every week and for a 20 credit student, 80 hours a week every week. It was brutal and exploitative imo. The one semester I took 12 credits, my quality of life, ability to retain material, and grades went up.

Re: Algorithms by Jeff Erickson

#125

Post by aspaceman »

avindroth wrote: post #40
aspaceman wrote: post #38

Earlier quoted context omitted.

You can still get value from a book that doesn’t give you all the answers. You can even get more value. Christ the answers have been all solved in papers, in literature, it’s all out there in small baby words what to do. But the whole damn point of math is learning to do it on your own. It’s like bitching that an art textbook doesn’t include draw by numbers in the back pages. “I just want to know I’m doing it right“…

Why are you so mad. Your argument is so overblown that even the modicum of value that is in your argument is rendered useless. Why don’t you ask people to invent math, then, and not show them the way? Why even teach anything? Of course people learn by checking their proof and being thorough, but it’s up to them. Solutions can provide certainty for people, much like how peers and peer review system can in science. Eve…

I TAed for this course. That's why I'm so mad. I have a personal stake in this game and you're talking out of your ass. I ain't asking them to invent math any more than I ask a painter to invent painting, or a writer to invent writing. Do they have solutions guides?

I'm not asking anyone to invent math. I'm asking them to work through the solutions and attempt to find a proof themselves. A _proof_. Not a solution. Christ.

Reading only solutions for proof-based mathematics misses the entire point of writing proofs. It's learning how to write. Do essay based courses have solution guides? Does your English course have a solution guide for the essay? How do you get better at writing? You read the written word. You read examples. Just like the examples Jeff works out tirelessly in every single chapter for you. Then you're expected to do it yourself.

Read the actual damn exercises in the book instead of talking out of your ass from the comment section. Each question requires at least a couple paragraphs of articulation. Some require multiple pages - single spaced. Are you asking Jeff to provide a 5000 page solution guide for these problems? Some of these are even research problems, writing all the solutions to them would likely award Jeff a Turing Award.

Just like writing, there's a lot of other resources and books to read out there. Plenty of things to reference and places to find inspiration in. But it has to be on your own. You can't just pull out "Great Gatsby Essay Solutions Guide" and use it to write your essay. I don't care if that's "just how you learn".

Christ. I'm so angry because every one wants to teach every subject like it's fucking Calc 1. And that's plain idiocy. The entire value I got out of this course in undergrad was technical writing. Learning how to actually "write" a proof, and not just nonsensically sling notation at a poor soul. Comparing Jeff's writing with mine, seeing where I tripped up, and trying again.

When I TA-ed for the course, I had to fail so many students who "had the right solution" and they did. They had the perfect answer, that they copied from the fuck next door and couldn't write about to save their life. The alegbra was exquisite, the typesetting immaculate, the writing and logic completely incomprehensible. 1/5 points. Every time. Most of them couldn't compose a single full sentence.

Fuck the solutions. And fuck your mentality.

Re: Algorithms by Jeff Erickson

#126

Post by totablebanjo »

oplav wrote: post #92
reasonabl_human wrote: post #67

Earlier quoted context omitted.

For someone out of the UIUC construct, does X73 mean various levels of algorithms courses? Could you elaborate on their titles or content? I am looking to self-study for core CS content that I missed out on in school after being largely self-taught, and courses that change the way one’s brain works sound like the right ones to take.

Yes, the X73 courses were theory based. Something changed after I graduated and now I think CS 374 is the algorithms course, but I'm not sure. If you want to start with the fundamentals, CS 173 (Discrete Structures) is required of all undergrad CS majors and is the first of the sequence (usually taken as a freshman/sophomore). The book is available online along with problems/solutions: http://mfleck.cs.illinois.edu/b…

Thank you for pointing out the starting course of the sequence!

Re: Algorithms by Jeff Erickson

#127

Post by aspaceman »

trevor-e wrote: post #93
aspaceman wrote: post #38

Earlier quoted context omitted.

You can still get value from a book that doesn’t give you all the answers. You can even get more value. Christ the answers have been all solved in papers, in literature, it’s all out there in small baby words what to do. But the whole damn point of math is learning to do it on your own. It’s like bitching that an art textbook doesn’t include draw by numbers in the back pages. “I just want to know I’m doing it right“…

> And I love that the problems remain difficult and meaningful And there it is, your argument comes down to gatekeeping. If all the problems have been publicly solved, as you said, then what's the harm of having a solutions guide? The cheaters can already find what they're looking for and it helps the self-learners who are actually trying to learn.

They haven't. A lot of the exercises are unsolved research problems.

You're missing the point entirely. You're just banging your head against "Different people learn in different ways". I am saying, that the thing this course, (that I took by the way), is trying to teach students is the skill of writing proofs effectively.

A solutions guide, as you imagine it, would not teach students to write proofs effectively. Since many of the problems in this book are of a research level, many are highly advanced. Many require many multiple pages of exposition to describe the solution effectively.

You would thus have to make a tradeoff. Remove the harder questions and write simpler explanations, so you can write a cost-effective and printable solutions guide. But then the "solutions" aren't actually solutions at all, but vague allusions towards the correct process. The student assumes that the "answer" are these vague allusions, "since that's what the solutions guide says" and the entire point of the class is bypassed in favor of passing more students.

It has absolutely nothing to do with gatekeeping, or cheaters. And quite frankly, I don't believe that advanced mathematics will ever able to be the most accessible thing in the world. And that's just its nature.

EDIT: Seriously if this was Calc, I'd totally agree with you 110%. A lot of people can only learn that stuff by staring at the answer being worked out. But that's not math man, and it's not what we want to teach people in this course.

Re: Algorithms by Jeff Erickson

#128

Post by aspaceman »

avindroth wrote: post #42
aspaceman wrote: post #37

Earlier quoted context omitted.

> they might be willing to pay you for them. I think we have some differences of opinion about the point of students not having the solutions. (Hint: Some people arent as greedy as you)

Ad hominem much?

How? What's the argument?

I thought his idea showed he was a greedy fuck, so I called the dude a greedy fuck. There's no ad hominem if there's no argument. Just came off as transparently greedy and selfish

Re: Algorithms by Jeff Erickson

#129

Post by zinclozenge »

ohdannyboy wrote: post #115
dkfjs wrote: post #49

Not proving solutions to textbooks seems to be a common theme in mathematics and theoretical computer science. It makes it difficult for those outside of the traditional classroom to learn the material. Instead textbook writers seem to have this adversarial approach against readers, thinking they’ll “cheat themselves” if they look up solutions or attempt to verify their work. Experts make mistakes, beginners would pr…

While I agree that this book isn't very useful for self learning, I have to defend the model you describe as adversarial. I took CS473 at UIUC (it's CS374 now) so I can tell you firsthand the course is brutal -- easily the hardest course in the CS program. You're given a LOT of resources through office hours and everyone uses them. The TAs are good at leading you down the right path instead of just showing you the an…

In the former situation you described, the actual textbook doesn't matter, it's all about the resources you described to help you along.

In a lot of cases, those resources just don't exist, even at universities. That's why worked examples and problems with solutions are so invaluable. In fact, they're so valuable, I've spent half a decade compiling these kind of resources for mathematics and physics, back when I was a master's student. I literally crawled through professor course pages manually downloading pdfs.

Re: Algorithms by Jeff Erickson

#130

Post by alexbeloi »

TheTrotters wrote: post #41
asicsp wrote: post #5

From https://jeffe.cs.illinois.edu/teaching/algorithms/hwex.html#... > Please do not ask me for solutions. With very rare exceptions, I will say no, even if you are an instructor. I recognize that my stance limits the utility of these materials, especially for self-learners, but I'm trying to optimize the learning experience of my own students at Illinois. The point of homework is not to solve that particular homewor…

I hate this attitude. It punishes students (and self-learners) who want to be as good as possible and who’d use solutions to get fast feedback. The right thing to do is to publish detailed solutions to textbook problems and create new problems for HWs.

It doesn't punish anyone. If you want solutions, then the book is not for you, that's all. The author is not obligated to accommodate every audience, or even a majority audience.
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