His teaching is not freshman friendly, but he puts a lot in improving the course.

Honestly speaking Geoff is an awesome professor. He has been trying to redesign CS125 since fall 2017 and made great progress so far. I agree that this is class is hard and the workload is heavy, but this is necessary for CS students, especially those who don't have previous coding experience.

Yes the grading policy wasn't clear enough. But this is the first semester after he redesigned the course so it is understandable. He is definitely trying very hard to improve this course and he is doing perfectly fine. His lectures are very inspiring and this course has office hours running by CAs nearly 10 hours every day from Monday to Friday.

Although his 125 class, as a introductory cs class, is little bit challenging, he is definitely doing a good job as a cs professor and designed so many online systems useful to students.

It is indeed a tough class but when I come this far I feels good and get more adept at doing MPs and quizzes. As long as you devote enough time in and follow Prof's instruction carefully you would definitely achieve a desirable grade.

I got mental illness after taking his class. His class is funny but the homework tortures me a lot. I am a freshman and I hope my rest of the college life can be better.

CS 125 was a challenging by rewarding class. I don't think the current rating of him (2.2) fits what I saw in my class (Spring 2018). Notes, quizzes, and MPs were all relevant. Everything was solvable, but not necessarily easy. You will learn a lot and have it be relevant knowledge in his classes. Put in the work and you will be fine.

While the course has a bit of a learning curve at the start, it is COMPLETELY worth it to get over the hump. Professor Challen runs his class well, and I learnt a lot in the course (much more than if I had taken CS 101). I went from having no knowledge of CS, to making a working android app. Highly recommend CS125 with Geoff - makes class great!

Challen is very passionate about teaching and he tries to make sure that help is always accessible. The grading is quite generous as 12% of students in Spring 2018 got 100% or higher in the class. However, the MPs are challenging and I would not recommend taking this class unless you are prepared to invest hours of work every week into the MPs.

I enjoyed his lecturing A LOT. I think he is pretty talented as a lecturer. He expresses things pretty clearly. EVERYTHING MAKES SENSE in this class. In Spring 2018, we had more than 100 CA to answer our questions and help with MPs But don't need to worry about grades that much, most people got A at last. There are several extra credit opportunitie

Geoff gets a lot of slack in this class but he actually works incredibly hard to make this a better CS class/school. Before this year 125 was a very easy class, especially for those with experience. Now, however, it is difficult, and extremely difficult if you don't have experience. Be prepared to sell your soul, but you will learn a HELL OF A LOT.

Explained things clearly and covered a lot of useful material. Only now that I'm at a different university do I realize how well taught CS 125 was. Some people love to hate on him because of the course difficulty, but it's worth it and you can definitely do it as long as you don't procrastinate.

If you go to class, follow the slides (to get participation points), do the daily hws, work on the MP early and get 100 for all MPs, then you will do well on quizes and midterms. Since the grading components are really nice, if you work hard, you will get an A. ps: MP are worth a lot, make sure to do them and get 100 on them.

I have never seen someone put so much effort in to teaching his students. Geoff really does care about teaching us and the amount of work he puts into it is reflective of that. Having a learned a little java prior to entering this class I thought I would be in for an easy A. Instead, I ended up learning SO MUCH. You will work for an A, but worth it

I don't really understand the Geoff hate on here. The class is tough, no doubt about it. But coming from someone with very little previous experience, his class is doable. He's also super active on the forum and on reddit which can be really helpful.

For fall 2018 CS125, Indeed it's a little bit too hard even for people who have learned AP CS before, but it's worthwhile to work your ass off and learn a hell out. ECs were given. Geoff earns my respect at least. Really fantastic lecturer. :D

This is one of the most amazing courses I've ever taken. It's REALLY hard for a starter to surive this course, but after coming along a long, long adventure, you find yourself harvest a great deal. The grading for this course is also generous, as about 50% people can get A. Take this if you love CS, or leave the seat for those who loves it.

CS 125 is more time-consuming than other intro courses, but Geoff has put a lot of effort into making it accessible to anyone (I personally had a little Python and no Java experience before taking CS 125). Daily quizzes, weekly homework, and biweekly machine problems (MPs) prevents slacking, but it's ultimately rewarding.

He is patient and very good at explaining topics . There is a lot of work, but if you do it and study for quizzes/midterms, then you will get an A. He is very active at answering questions on the forum. The CAs/TAs are very helpful. There were few bugs in the assignments. The class was very well-organized.

Geoff clearly really cares about his students. You can really tell that he has put in a lot of effort to make this class accessible to as many people as possible. Don't get me wrong, this is not an easy class, but there are many resources available to help you do well.

Geoff is awesome. He really cares about his students and is extremely helpful. I wasn't sure if I wanted to do CS but now I know I do. A word of caution: this class is hard and moves quickly. It's easy to get an A if you stay on top of it though.

There is no doubt that this is a hard course. Actually, it is the hardest course I have ever taken, even much harder than 400-level math courses. However, I do think Challen is a good professor. He is passionate about teaching, and always willing to give students help. The MPs are hard, but it turns out that we can learn a lot from this course!

Don't get me wrong, CS125 is hard even to the ones who have taken ap in high school. But I honestly think geoff tries to guide us to understand the concepts. Also his grading system is really generous. I absolutely bombed my first midterm(68) and still end up getting A( 96) overall, he also gives lots of extra credits

I had no coding experience coming to this class. Not gonna lie. This class was tough. Spent more than 10 -12 hours a week alone on Machine Problems. However, Geoff take feedback pretty well and will hear his students out. Going to office hours consistently will help you do well on this class. Class doesn't get easier, but its gets better.

Very good class. Everything is structured extremely well, and it's clear that Geoff has/is putting in a LOT of work towards improving the class. His lectures were very comprehensive, and whenever I didn't understand something, I could just look back into the lecture video. He cares a lot about his students, and the grading is very generous.

Really good prof, seriously.

Geoff's CS125 class is fantastic. He has improved it constantly through feedback, and it will only get better. The class is hard, and will be a huge challenge for beginners. However, towards the end of the course, you will know all the work was worth it. He really cares about every student and really made the 9 AM lectures bearable.

His lectures were absolutely amazing, I know my stuff but I still learned a whole lot! His lectures are mandatory and you do have to keep up with the slides to get credit, but you also get 10 drop lecture attendances! His class isn't the easiest but he does his fair share to make an A worth what it is. If you work hard, A isn't an issue.

Genuinely cares about teaching and his students. Sometimes he went too fast and this was very frustrating for beginners. However, he responds and changes according to anonymous feedback forms, which I really appreciated. There is daily homework and mandatory attendance, but also a generous drop policy.

This man is strong-minded, but won't act on impulse. We made an APP to recommend easy gen-eds, and while Geoff doesn't personally like the idea, he gave fair feedbacks of our project. He moves the class a bit fast, making the 4-credit-hour-class appearing like 6, but his lectures are decent. About MPs - beginners have to go to office hours!

It is very easy to get an A/A+ in his class, but there is a decent amount of work to be done. HW problems everyday and MPs biweekly. If you put in the work, you will get an A guaranteed.

Geoff is really nice and he's passionate about computer science! This class requires a fair amount of work but it's an easy A as long as you do your work. The MP of this semester is harder than previous ones but he gave an extra drop for MP and apologize in class. I went to his office hour once and we had a really nice conversation.

Great professor, very passionate about CS materials and thinks for his students. I was a beginner in programming and I did have a bad time in the first few weeks, but it's not hard once you get used to it.

Geoff is a super great teacher and really cares about his students. I had almost no prior coding experience coming into the course so the quizzes and MPs were very challenging to me. This class is definitely hard.

Fantastic teacher and human being. He really cares that students succeed and has organized CS 125 with daily homework assignments that really reinforce the concepts. Super innovative approach that I wish more of my other professors would take with the online forum and mobilizing such a large course staff. You will learn so much in this class!!

The class was straightforward. Go to lecture, do the daily homework, start MPs early, go to office hours and ask questions. This is not a low-time class, but it's very worth it. You definitely need to go to office hours to finish the MPs . The homework was incredible. Wish I still had access to the homework problems honestly.

Excellent guy! He wants every student to succeed and will do whatever it takes for them to appreciate the subject. The class has a good mix of fun and hard work. Put some effort and I guarantee youll get an A and even pursue this field for life. Do take this class, even if you have nothing to do with CS.

Geoff is a great lecturer. He made you work for the class. Though the MPs are hard and extremely time-consuming, it was all worth the timeone of the best courses I have ever taken at UIUC. You would learn a great deal from the class. Take the class if you have time and are ready for some challenges.

The best CS prof to ever exist :-)

If I have to rate him in detail I would give a 4.8 for him, but there is no option for it. He's the one of the best instructors I have for fall 2020. The workload is really heavy since there are 5 lectures per week and also a HW followed after the lecture. The only bad thing about this course is the machine project. Would be better if he removes it

I was definitely a beginner in CS, but Geoff is an extremely caring professor and does a really good job of explaining all of the material. The class is hard though, with homework due every day and five lectures a week. Luckily the class is well organized and has lots of office hours, but even still the quizzes and MP are a real pain.

Geoff's teaching style is incredibly clear and concise. The daily lessons are structured well in content and also delivery. I admit, for someone truly coding for the first time - the course will take you 1-2 hours every day. If coding isn't for you, however - it's best you realize it as soon as possible. (class median: 93)

Need to have some experience in CS or a friend who can help you out! Otherwise, you may spend hours on the daily homework problems! You get several drops on different assignments, but you will not do well in the class if you don't have what I've said is needed.

He is a very good professor and he knows how to help his students very well. I was brand new to programming and this class really helped make me understand it more. The class is a lot of work and you need to watch the walkthroughs the Professor puts online to understand what is happening in the class.

He is the best. MPs and weekly quizs could be tough, but you'll be OK.

He is the best professor I ever met, really. The daily practice is great. The Mp is a little bit hard, but if you work hard and spend enough time it would be great. However, the quizzs and exams are hard, if you want A, you need to pay more attention to the homework and Mps.

Geoff doesn't like students sending him individual emails but it makes sense because you can literally get the same questions answered on the forum in 5 minutes or less by him or by the staff. His lectures are very thorough and helpful and he's very passionate and knowledgeable about CS. Great professor who's always got your back.

By far my favorite professor at UIUC so far! The daily lectures were perfectly paced and interactive! Having taken another CS class that isn't going as well, I really miss the structure of CS 125. Super easy to get feedback on MPs or general help with the content.

Awesome class

Most people I know either love or hate Challen. I'm in the first camp. He's the best professor I've had at UIUC. Challen is extremely well organized. He is upbeat and intelligent. I'd never coded before taking CS125, and I'm getting an A. If you actually take the time to study the daily lessons then the homeworks and mps are pretty easy.

The class website is very well-designed and the grading is generous. The MPs are very difficult for people with limited prior coding exposure but the staff is always there to help. Quizzes are difficult at times but the lowest three quiz scores are dropped from the final grade. Highly recommend for anyone looking to learn basic programming skills.

Geoff is what I wish every instructor was. His lessons cover absolutely everything you need to succeed, replies instantly on the forum, cares about the success of the students, grants extensions, and encourages you every step of the way. The learning environment for CS 125 is set up extremely well to provide you with all the help you need to learn.

Class is moderate hard and so as the quiz, but like this professor so much that this is actually the first time that I figure how to code.

He's a pretty great teacher honestly and I've really enjoyed learning Java through his lectures. The HW and quizzes can be kinda tough so I recommend studying the past week's lessons to prepare. However, I can't recommend it enough if you're willing to put in the effort.

The class is broken down into daily tasks. You have a lesson everyday (relatively small lesson) and all you have to do is complete the homework lesson at the end of the lesson. It's not that bad, usually took me 1 hour a day depending on difficulty. Just stay on track, don't fall behind, and you'll be fine.

CS 124 is permanently online, so its format is quite different from other courses. That being said, there's a lot to learn and I think Geoff is a great prof with extensive experience and knowledge. He's active on the forums and answers all student questions, whether they'r directly related to course material or not, and the lessons are interesting.

great professor; knows his stuff; it's an easy class if you put in the effort

Just want to share some thoughts about Professor Challen: He did a great job in making our course website more stable. Then he gives specific suggestions to all my problems posted in the forum. I know computer science class is abstract and even tough for some of the students, but as long as you start studying, it will be ok.

Not that hard for java beginners (especially looking back from cs128 lol). The MPs and homework are challenging but manageable. Put in effort and you will be fine.

To succeed you really just have to stay on track with the daily assignments. The class is also quite forgiving as there are numerous quiz and hw drops and coding problems do not subtract points for a wrong attempt. You also have a very clear idea of what your grade is which is very helpful. A lot more good to be said such as the help site.

Understands that beginning Computer Science in college can be really scary and provides multiple lesson videos that slowly build up beginner skills. At the same time, Challen reminds you that what you put in is what you get out of this class. If you don't put in the daily work, you're not going to understand what you're doing.

Prof. Challen is just wonderful. He is caring, responsible, and passionate about teaching!

Geoffrey Challen is a great professor. He is caring and very knowledgeable about computer science. The class is beginner friendly but is a harder adjustment for people just learning to code. This is acknowledged by the three quiz drop and nine homework drop policy. Stay consistent, don't skip lessons, and do practice problems, and you will succeed.

Class is somewhat easy if you've had prior experience in high school, but likely more difficult for people new to CS. The site the class is on is very impressive and it is somewhat convenient to get help. The course can be done in Java or Kotlin. Just put in the effort and it will be rewarding, especially so for the newbies.

I had no prior coding experience & I learned ALOT within one semester. There is a lesson & homework assigned everyday, with a weekly quiz. There is a help site that you can join for help, that honestly saved me loads of stress. You are allowed 9 homework drops & 3 quiz drops. He is a great teacher but have not seen or spoken to him once.

Professor Challen's lecture videos are super helpful with understanding the materials and preparing for the weekly quizzes. The TAs & CAs are also super friendly in answering questions I've throughout the semester on homeworks and the MP. Great class overall!!!

Professor Challen is a very smart man. He has set up an impressive ecosystem on his CS website with multiple voices explaining a concept and ample practice problems. In terms of coursework, his course is fast-paced. Some advanced topics are taught in this introductory course but in an approachable way. Quizzes are difficult; take the practices.

Moving CS 125 to online teaching is a milestone of Computer Science education at UIUC. I like his quote: "Do little bits every day." This is so true and it will always influence me and my future computer science career.

This was my first ever CS class and I actually really enjoyed it, despite its difficulty. Biggest problem for me was the time sink, but I did learn a lot! Challen himself sometimes seemed a bit rude on the forum, and the MPs made me feel incredibly lost. I would recommend using the help site a lot. It's an easy A if you just put in the time.

The course as a whole is pretty good. Challen's videos and walkthroughs are the best and he is quite personable. On the forum he does come off as condescending and definitely has built a hierarchy so that he can have as little interaction with students as possible. Overall, CS124 has a beautiful website and a great overall structure.

If you put in work this class is an easy A. That being said there is a lot of homework and weekly quizzes, although I thought the class was totally fair and think anyone can succeed. Do not get behind on homework and the MP, try to do all of the homework a bit early and take advantage of the help site. I chose Kotlin, and enjoyed the class greatly.

There were very few times when I felt lost in this course, even as a beginner to Java. Just make sure to do all of the homeworks. Grading policy is very fair.

This class is a good introductory class, but if you haven't taken APCSA, it can go by really fast and it can be hard to keep up. If you have taken it, then it becomes a lot of review and not that worth it. The lectures can be annoying at times and long, but they are easy enough. The HW was never too hard to manage and the help was good too.

I had Java experience before, though it could be difficult for those without. All interactions are with course staff at not Challen, MPs were hard (don't delay those), and voice recordings got old fast, but the course is designed for everyone to get a good grade (with a good amount of drops). So you can learn a lot and get a good grade (avg. 95%).

The class is completely online and asynchronous. Daily homework assignments, weekly quizzes, and no final exam. Towards the end of the semester, there are 2 MPs. These were tough because support is hard to find and they're new. The website was very well organized though, and many drops were offered for homework and quizzes. Def recommend!

Even if you didn't take APCSA, which I didn't, the class is still very easy and it's not hard to keep up. Expect 40-80 min of work a day. Love the help site and the help staff! Some of the walkthroughs should be abridged, but most were fine. Quizzes are very straightforward, and you get drops. I would definitely not call it a nightmare.

He's a great professor also a nice person. The syllabus is kind. The challenging tasks are the MPs, also the weekly quizzes. Overall, you work hard, you will get an A

I had almost zero experience in programming, and this was the perfect intro to cs for me. prof challen always go above and beyond when explaining concepts. My favorite memories from this class are when he takes 10 minutes explaining a concept, then write the whole logic in one line.

He's cool

Probably won't have face to face interactions with Geoffrey, but his lectures were clear for the most part.

He clearly knows his stuff and can teach it pretty well, but it's just confusing when you get to the project. Generally, I usually felt pretty well about the course until the project, but still, it wasn't that hard bc of AI.

Lectures were clear, and while the prof doesn't provide much 1-on-1 help, the weekly quizzes and challenging MPs kept me on track. I found Unstuck ai super helpful for quiz prep - saved me some time.

Great instructor, made learning Java fun and informative. Most of his homework is easy but some will stump you. Excellent material to prepare for exams. The final MP for the class is the most difficult aspect of it which you may find to get stuck on. Depending on class TA's you may be helped or provided little direction but the project is doable.

This is a very good course that teaches you how to write and implement codes. Although there is a quiz once a week, you'll be fine if you review the lessons carefully and do some practice problems. Professor Challen is a good instructor, and he often answers questions I posted on the forum. The grading policies are also very lenient. Easy A.

It is an online lecture based class. If you are new to coding, please for the love of god go to the in person discussion to get help if you need. Online tutors do not help at all. Other than that, no matter previous experience, you will be fine if you put the work in. If you dont put work in, you will suffer even if you are good at coding.

I think that this is a pretty good course, with good and helpful videos, but it is definitely intense. You can take it as an intro class but it will probably require a fair amount of work if you haven't coded before. I think that the machine project is somewhat poorly managed, but it is very doable especially with the extra credit offered.

i really enjoyed this course. the difficulty of the course depends on your experience coming in. i had no experience in cs at all but i found i could learn everything i needed through the course generally. BUT, some things aren't explained really clearly in the lessons and you may benefit from outside resources and def the tutoring site...

decent - MP's are being improved -

Geoff, in my opinion, is a decent professor. He makes most things clear and gives you plenty of resources to succeed. This course is A LOT of work though. You'll be doing daily assignments and homework. It can be difficult but it is possible. My best advice for taking this course is to pay attention, ask for help, and google things occasionally.

It's a pretty manageable course as long as you put the time and work in. I did learn a lot and the lessons were usually pretty clear with multiple explanations for topics. There's a lot of time commitment with daily homework though. The MP was also a pretty big jump in difficulty from the work done throughout the semester.

(Had prior Java experience) The everyday lectures and weekly quizzes were fine. Grading was fair. The MP was atrocious. Thrust into android programming without explaining most of what we were doing was recipe for disaster. Stack up extra credit from early deadlines so you can avoid doing the last parts.

Good lessons on CS124. I took APCSA in high school but didn't understand anything but I understood everything that was taught in this course

Quizzes are 70% of course grade, but you can make corrections on them the following week after you take them the first time. MP is stupid and really complicated, but Challen is very nice and his videos are very informative and teach you well. It is very important to stay on track of daily lessons to keep up in the class.

The class was easy since I was not new to programming. However, the project was a bit difficult. Make sure to do well in the first few quizzes since the last few can be hard. There is a quiz every week and no final exam. The quizzes offer a re-take of the previous week's quiz. I do think that he and the tutors can be kind of rude sometimes.

A fully-online* introductory programming class offered in two languages, probably easy for people with prior coding experience and challenging otherwise. The class is well-designed for an online class, but sometimes not engaging with too many videos. Changes coming next semester include (probably) required in-person discussion sections.