You'll never see or hear from the professor so it's entirely based on your TA. Follow the instructions and do exactly what the manual tells you and it'll be fine. You'll probably get docked points on dumb things and there's nothing you can really do about it. My TA never went over what we were supposed to do at the beginning of each lab, even though he was supposed to, but it wasn't too difficult to figure everything out.

4AL is a behemoth. You've probably heard that the grading is harsh and that you're going to spend a lot of time on lab reports. It's true.
.
You're given all the materials required for this class (a lab manual) and you go to section having read up on what you are going to do in lab. The labs investigate different physical properties like mechanical energy, friction, gravity etc. Most labs (not lab reports) I was able to finish in two hours. However, the last one I had to do twice because I ran out of time. Make sure to collect good lab data.
.
The TA's are instructed to deduct a lot of points for mistakes to spread out the sections, as there are up to 20 kids in a class. Homework 0 (the first assignment) covers the policies of the course. The next 7 labs will take you at least 10 hours to perfect (to get a good grade), re-reading and editing to the specifications of your TA. You'll learn when you get your old labs back what the TA was looking for and should correct for it. Put in the time and hope you come out on top when it's all said and done.

You've probably heard that 4AL sucks. That's only true if your TA sucks, which is hit-or-miss. My TA was fine, so I had a decent experience. Yes, it's a lot of work, but you're only in the lab 1-2 hours per week (even though the class is slated for 3 hours, you usually finish beforehand on most labs) which makes it very manageable.

The lab manual is your bible for the quarter. Read it before doing the lab (only takes 20 minutes) or you'll be dead weight to your lab partner, and probably won't finish on time. If you walk in knowing what you're doing, the labs won't take more than 2 hours. I finished the last lab, which was supposed to be the longest one, in 90 minutes AND we had 3 people in our lab group, meaning we had to take 50% more data than the other groups that had 2 people (everybody needs unique data).

Read the lab manual after the lab, too. Have it open while you're working on the lab report and it's easy to hit all the points that you need. Hamilton literally tells you what to include in your lab report, and it was surprising how many people didn't read the instructions. Extra credit is offered on each lab; this often requires taking additional data. This is Hamilton's grading scale: if you fall within 1/2 standard deviation from the mean, you get a B. If you fall above 1/2 SD from the mean, you get an A. If you fall below 1/2 standard deviation from the mean, you get a C. If you do all the labs, you are guaranteed at least a C. All bets are off if you miss one or two.

Overall, ignore what people say about 4AL. Yes, I may have gotten an A, but in the end it's only 2 units. All you have to do is follow instructions from the lab manual, listen to your TA, and you'll do fine since most people expect to get a C and therefore choose not to do either of those things.

This is one of those classes that you might develop a sharp adversity to like I did (my TA was Zhenyu She). Physics is my favorite subject, but the lab hardly focused on physics concepts, only the very basics. The rest is tedious, at times frustrating, stressful if you leave it to the last night, but somewhat satisfying when you finally finish the lab report. The labs mainly train you to write in the style of professional scientific works, and the grading is rigorous. Not gonna lie, I definitely teared up multiple times doing labs for this class lol, but I also didn't read the lab manual beforehand like some of these reviews said to, and I would usually take 2 days to do each lab. For some reason they took me forever, and the last and longest report (your final) took me 20 hours. So MAKE SURE you reserve time for this class.

That being said, it's only 2 units!! Just focus on passing and following the manual. It's annoying that a class with such a harsh curve but low units takes up so much out-of-class time.

The worst class ever at UCLA. If you are taking this class it is because you have to cause of your major, so I will list the keys to do well.
-You will never see the professor and the TA grades all your work, so become best friends with them. I went to my TA's office hours every week and was always the first person there. I made many mistakes in lab reports and didn't lose points because he overlooked them thinking I was a good student.
-Talk about how the calculations should be preformed with the TA in office hours and the reasoning behind the uncertainty calculations. I was able to convince my TA multiple times my way of finding uncertainty was better so it was almost as if my report was the rubric helping me get good grades (another reason to become friends with the TA)
-The lab reports take many hours, most of them 1000+ words long and need nice looking charts from excel so start early
-Practice editing charts on excel so they look good and practice basic excel coding before you start
-One thing I like to do was write the excel code before lab. After collecting the raw data I would input it into excel and the code would automatically produce the graph I wanted, I could check and make sure the data was correct before leaving lab or redo the experiment until I got correct data
-Read the lab manual before not enough time in lab to read it and do the lab
-Take the class with one friend in your section and can choose one lab partner to be with for the whole class (just set nice to them on the first day)
-Be very careful about lab reports one or two mistakes takes you grade from an A to a B, the grading is just dead awful.
Overall this class is a pain, but at least it is not curve to a B- anymore so it is slightly easier to get a good grade. Pro tip this same class if offered at UCSD and UC Irvine over the summer and in these college over 70% of students get A's and all they do is very easy worksheets. So u could take it over the summer there and get away with an easy A by doing no work (I wish I did this)

Your 4AL experience will highly depend on your TA. Forget about the professor because you will never see him. If your TA is good, 4AL won't be so painful.
What do I mean by a good TA?
1. Give clear instructions before the lab starts (including the set-up, the data to collect, how to avoid errors, etc).
2. Tell you his/her criterion for the lab report(what to include in the introduction, method, analysis, conclusion;how to correctly label your graphs)
3. Helpful. (My TA adjusted our equipment himself when we couldn't get the right data)
If your TA does the things above, congrat, you'll be fine. If your TA doesn't explain the experiment/the criterion/doesn't give a shit, drop your session and get a good TA.
My TA is super helpful so I didn't suffer as much. Still, be prepared to go to office hour every week and ask your TA to check your report before submitting it. Also read the lab manual before going to the lab. It is poorly written but at least go over it.
As for the workload, I spent 2-3 hours to process data and 1 day to write the usual reports. For the final one, I probably spent twice the work as the normal ones.
My TA is Jingwen(Aaron) Zhang. Take his session if you had the chance, that's probably the least painful 4AL experience you can possibly get.

This class suuuuuuuucks. Reports are a ton of work and are graded really harshly. The syllabus literally says "you are competing against your classmates for the curve." Give yourself at least 2 solid days to write each report, follow the lab manual closely, and get this class over with.