Rohr was Honestly not that bad. His lectures weren't the most energetic, but if you are in any way interested in the material, they are useful, and easy to learn from. My only knowledge of C++ before entering this class was from PIC10A in the spring of 08--So, I did not spend AS much time 'learning' concepts as much as implementing them in the projects. I put a lot of effort into this class, and was able to get an A, but this came from Diligently going to office hours, both the professors and the TA's, starting early, and going to section every week. Unless you are just amazing, you have to put in at least half this amount of effort if you expect to do well. However, I am a CS major and this was my most important class this past quarter (amongst EE1, Math 33A, and Phys 4AL), and I couldn't imagine being a ChemE or any other type of engineering and putting that much effort in.
But back to the class.. the midterm and final were impossible to finish. Too much to actually THINK about in a short amount of time. However if you are like me--I always think of my grade relative to the other people in the class, and its not too hard to stay above average. You can't really 'study' for this class, because its really just testing you on the things you should know from the projects--if you understand the projects, for the most part, you have a good chance of doing well.

Doctor Johnathon A. Rohr is a very kind, elderly man, perhaps one in his mid-60's. He is helpful and provides input during class. He'll give you his full, undivided attention when you ask questions. His disposition is that of a gentle demeanor. Overall, I'd say he cares much for your learning.

Now, what you've just read above is true according to my opinion. Note that I've only discussed his personality. On the other hand, his teaching is dry and his project organization sucks.

Before I go into my rant about my quarter with him, I'll explain the mechanics of his class. I don't recall what the exact weighted percentages are, but Homework and Projects are worth around 40%, Midterm is worth around 25%, and Final is worth 35%. There were four homework assignments and six projects given out during my quarter; homework assignments were usually complemented with the upcoming project to facilitate project production. The midterm and final were similar, in terms of format. For those who are knowledgeable in C++ (this class covers C++ only), some of the stuff midterm covered were strings, arrays, I/O, and those loops and if-statements. Average for the midterm was around a 58%. The final was one-third pointers, one-third classes, and the rest was various topics from the quarter. Average for the final was around a 48% (the Fall 08 class of Smallberg, another CS 31 teacher, was around 85%, I believe).

The aim of this class is to pay close attention to minor details; make sure everything follows exactly as the instructions instruct. For those who are new to the C++, such as I before I took this course, you're going to type many lines of codes (obviously) with many punctuations. One missing semi-colon may screw up many things. Thank the creators of Visual C++ (and God...and Satan, for Satanists) for creating the Debugger. Make sure you learn how to use the debugger; it's helps tremendously during the homeworks and projects. Copy and paste whatever error/prompt messages he wants your program to spit out; that'll decrease the chances of errors in your program. Overall, be anal about every little thing, and you'll do exceptionally well on the homeworks and projects, as far as correction goes.

There are two reasons to start on projects early: they're obviously time-consuming, as other posts mention, and you'll be able to develop questions about the speculation early on. As mentioned before, I had no prior knowledge of C++. I would be stumped on a certain part of the project because Rohr hadn't taught enough of the language for me to finish the project. By the day before the project is due, he would finally teach everything there is needed to know to finish the project. Each time, I would be pissed and frustrated. If you're a n00b, make sure you start on projects early (I recommend as soon as it gets posted on the class website), so you know what to ask your TA and/or Rohr. That's one of the worst experience I've had with this professor.

Other horrible experience: he updates the restrictions he puts on the project when the due date is close. By the time I finish with a project, with all joy and glee any mere mortal could possibly have, he updates us with some sort of badass restriction that causes me to make some major/minor changes to my project. Have different copies of your project at different checkpoints at your disposal to remedy this annoyance.

This class tests your ability to learn a few operations and apply logic to that knowledge. It will take flexibility in logic and creativity (I'm not sure if "creativity" is the right word) to work efficiently on the homeworks and projects; I believe the time spent on the projects heavily vary on those two factors. Succeeding on the exams will require you to be meticulous.

Compared to Smallberg and the other CS31 teacher, Rohr pales in comparison. Smallberg has a much better personality, in my opinion; he's funnier and livelier. I don't know about the third teacher (his name starts with the letter 'N'), but I think he's young and energetic.

Here's my priority guideline:
1. Take Smallberg or another professor.
2. If Smallberg/other professor is full, you can take Rohr only if it's absolutely necessary to get rid of CS31 at the moment (Rohr uses the projects made by the other professor of that quarter, so you'll be able to avoid the lack of project organization)
3. If Rohr's the only one teaching that quarter, you are advised from taking CS31 that quarter, unless it's absolutely necessary to take it (Rohr will be making the projects, so he'll often be making updates that cause you to change some part of your project. You've been warned)

lol, he's not that bad.