Professor Christou is one of the most caring and dedicated professors I have ever had; he hosts 2-hour office hours six days a week. That being said, this was the most stressful class I have taken during my time at UCLA, and proved to be extremely difficult for almost everyone in the class (apparently harder than most math/engineering/CS upper divs). Many will choose to take Christou again because of his generous curve, but if you do end up having a class with him, just make sure you take your grades and your workload with a grain of salt so you don't end up exerting yourself too much mentally.

Grade breakdown:
Midterms x2, 25% each
• These midterms were ridiculously difficult; I studied the same amount for both, ended up with a 43% on the first one and 26% on the second, and felt like whatever score I got was just a matter of luck. Midterms were open-note but averages were still 28% for both, and if you scored above a 30% you were in the A range.
Homework 15%
• There were NINETEEN homework assignments in ten weeks, with an average of 4 questions per assignment. They take up so much time and are ridiculously hard as well; personally don't feel like Christou was very helpful during office hours since he would often tell me to look at the answer key, but maybe I was just asking the wrong questions. Initially homework was stressful because they graded on accuracy, but they switched to grading on completion mid-quarter after realizing that it was impossible for people not to fail their assignments. Hopefully they keep it that way for future quarters.
Final 35%
• Similar to midterm, just felt like 3 hours of suffering to me. One person tried to leave early and give up on the final, but Christou looked through his paper and asked him kindly to sit down and try to complete it. You could tell it was because he cared for the student and wanted to him to succeed. By the end of it, I was so glad the class was over.

TL;DR: Overall, this class was really emotionally difficult for me and was extremely challenging. Christou really is a kind soul and is well-loved by his past students, and I can see why – he cares for his students and always told us to study well because it would be helpful for our future. But if you choose to take this class with him, be prepared for an intense workload and horrible raw scores, though you can always trust the curve.

This course makes me feel like a complete RETARD. I have no complaint at all regarding Professor Christou, as he is a really helpful professor. I could say that he has tried his best to deliver the course materials, but they are still so hard for me. The average for exam1 is around 27/100, and the final is even harder than exam 1. When doing the tests, you will find that your efforts paid in reviewing past exams and hws are meaningless, as there are very few similar questions.

This class, taught in fall 2021, requires students to use R to analyze several datasets containing the price of major stocks. Don't worry if you have never used R before; instructions are given before the beginning of the class, and you just run through his given commands on R. Professor Christou is clearly passionate about teaching and wants to spread the knowledge to the class. He's a very approachable if you have any question regarding either the course material or guidance. Overall, I recommend this course to you if you are interested in analyzing the stock market data with R in future, or if you are interested in getting guidance from a very knowledgeable professor.

Christou is definitely not a bad professor/lecturer, but I think he's slightly overrated. His lectures go REALLY fast, so sometimes you have to look at the lecture notes that are posted after class, which can be annoying. Homework was medium difficulty, and the overall workload was manageable.

The thing you need to remember about Christou's exams is that their difficulty is balanced by a FAT curve. The class is medium difficulty, but people think it's really hard just because they get bad scores on the exams. While you definitely have to put in effort to get an A, it's very achievable. Probably my favorite aspect of the course is that Christou views exams as learning opportunities rather than opportunities to punish negligent students. He makes the exams really hard and doesn't tell people the letter grade cutoffs until the very end of the course so that people focus on learning the material rather than achieving X% on their overall grade. If you regularly put in effort, you're pretty much guaranteed to pass the class, even though it might not seem like it.

You can tell that Christou cares a lot about student learning just by looking at how frequently he holds office hours. However, he can often be rude or impatient when students ask really basic questions. To some degree I don't blame him because people sometimes ask things that they could easily find the answer to themselves, but a lot of the time his frustration is unwarranted.

Overall, the main thing I found lacking about the course was that there was too much emphasis on derivation/matrix manipulation and not enough emphasis on the ramifications/interpretation of the results that Christou showed in class. For example, one of the bedrock principles of linear models is that we pick the linear combination of random variables that minimizes the mean squared error. While Christou touched on this briefly, he didn't really go over why this is so important, and mainly just focused on deriving all the least squares formulas. You could easily get an A in the class without knowing how this concept relates to actual statistical modelling, and why it's such a crucial concept to understand. I'm probably being a bit unfair here because I feel like this is an inherent weakness of the lecture format, but it's a flaw nonetheless.

Pros: Heavy scaling on exams, around 30% was an A for the midterms. Many office hours. Had a great TA, Conor, (definitely recommend going to his discussions).

Cons: Lots of homework, 2-3 a week, ended with 19 homework assignments total. Christou goes through the material very quickly in lecture and jumps around in his handouts a lot. Sometimes, a lecture might not even have a handout, overall, kind of disorganized, so come in expecting that. Exams are nigh impossible to complete, not good for mental health.

Tips: The exams are open notes, and many similar question types are covered in lecture and homeworks. Therefore, some questions, you might just end up copying the process from your notes. Understanding how concepts are related and being able to identify problem types are a very useful skill in the exam (again, since open notes, being able to identify the problem might be 90% of the work). Also, the Penn State stats 414/415 notes recommended below explained concepts pretty nicely.

Overall, this is a demoralizing class with a lot of content, but Christou's heavy scaling makes it fine in the end, so just keep in mind you'll probably do ok :)

Christou is the most unorganized professor I've ever had. He doesn't teach in a linear path and countlessly flips back and forth between his handouts during lectures. He can't teach one topic without referencing 3 previous topics and takes too much time clarifying concepts no one was confused about. I stopped going to lecture because I didn't learn much; I just did his handouts at home and used online resources (look up PSU's online mathematical statistics class, Stat 414). The curve was indicative of how poorly this class was taught, with a 53% being an A. Print the solutions to old exams and bring them to the midterm since he reuses questions.

I like professor Christou despite his tough tests. I believe passion is the most valuable quality of a good lecturer, and you can definitely see it in professor Christou. He holds office hours nearly every day, and he is always willing to respond to emails and gives detailed explanations about concepts.

Yes, you can't get an easy A in this class, and yes, you have to spend many hours in this course to master the material truly. But taking 100C with him will help you more than if you take it with a professor that gives everyone an A. Believe me. I regret taking 100A with a very nice professor who gives everyone an A because I later found out I don't master the content in probability theory and encountered many obstacles in other courses that build upon it.

Professor Christou might be the only stats prof here who actually cares about you. Yes his tests are brutal, his homework makes you want to cry in the middle of the night, and sometimes his material is so challenging it makes you question your future academic path. But at the same time, he is the kind of professor who will push you to be a better, more prepared student.

some logistic:
15% homework (there's like 15 homework)
20% midterm 1
25% midterm 2
40% final

Homework is graded on accuracy, but with the TA and some smart kids in your class, you should be able to get 100%. Both midterms are hard, buttttttttt the curve works in your favor. For my class the average for the first midterm was around 22, and if you score above high 20s you are in the A range. For the second midterm the average was around 20 as well, and if you score above 25 you're in the A range. Coronavirus happened so Christou made the final optional, which just shows you how much he actually cares about his students.

This quarter is rough, but I am happy that I took 100B with Christou even though people keep saying it would be suicide. He actually cares about his student learning and have 20 hr of office hours per week. He even remembers my name ??? (Im an internatonal student so my legal name is very hard to pronounce for him but he still tries to do it????????)

If you like challenging yourself, please take 100B with him. He is such a great professor and you will end up loving him.

Honestly, Christou is the best professor I've ever had at UCLA.
You can really learn a lot from this class if you put your effort into it. He really cares about his students and hopes them to be successful. He gives about 12 hours of OH every week, and he is always there ready to help you. He knows his stuff and what he expects us to learn in class.
As all of you already know that this course is extremely hard, the average of the midterms is just a little bit over 20, and it's becoming lower and lower every year. There are in total 16 homework assignments this quarter. You need to be prepared for all of these before you take this class.
In the exam, you need to clear your mind to do it. Sometimes you will find yourself cannot solve any of the questions on the exam, but just write down what you know about related to the questions, then you will receive partial credits where most of your points come from.
During the quarter, you need to be optimistic about your grades and assignments. Professor Christou is not meant to make difficulties for all of us, but he wants us to learn something beyond the scope in the exams. He told us that "grades are just numbers, what matters is understanding the material". Try your best to learn, not just to try to get an A. You may feel bad about it at first, DON'T DROP THE CLASS simply because you thought you did not do well in the exams. At the end of this class, I believe you will find Christou a very good person.
Enjoy it.

I love Prof. Christou as a person but not as a test maker. I had to study my ass off, sacrifice my happiness/health/social life throughout the qrt to get As on both midterms. (Though I failed the final and ended up with an A-, which sucks.) Some naturally talented people grasp the material faster, and the professor does not understand his exams are just not possible even to some most hardworking students, because of the presence of those talented students in his class (those people who would get 60-almost 90 regardless when the averages were around 35-40)..

If you have a good mathmetical background and wanna get the most out of this course, go for it.

If you want an A, but don't have a good mathematical background, and want to keep your health/integrity/social life/happiness, take this class with a different professor.

But I have to comment on how great this Professor is. I'm a senior, but I haven't seen any other professor who is as kind, caring, and friendly as he is. He is genuinly interested in his students and wants to get to know them more. Although I hate his exams, he is too great a professor I would still prefer his course to some other professor's.