Unlike undergraduate school, there is no requirement at UCB that you accumulate any specific number of credits (units) before you take your doctoral degree. However, a full four- to five-year program is the rough equivalent of 120 units. Therefore, as a graduate student, you should enroll for at least 12 credits every semester. (Enrolling in a minimum of 12 units is a Graduate Division requirement for graduate students who have not yet advanced to doctoral candidacy.) Enroll in your courses, and then fill out the schedule with Research (299) credits until you hit a total of 12 units. But you should not enroll in more than 15 credits except in exceptional circumstances.
To advise you to enroll in 12 to 15 credits per semester is not to advise you to enroll in four or five three-credit courses. Courses, while valuable and interesting, can be a distraction from research, and unless you complete a progressive program of research culminating in the dissertation, you cannot take the doctoral degree. And unless you obtain the doctoral degree within five years (perhaps 6 for Clinical Science, for which the internship adds an additional year), you are in danger of losing your financial support. There is a temptation to take lots of courses -- not just because it is easy to take classes, and not just because many classes are interesting, but because many seminars are offered only once on any topic, and you will not want to miss anything. Do not succumb to the temptation to take every seminar offered by every faculty member, in the belief that you will never have the chance again. You will get that chance. You may be able to audit the course, learning the topic without investing precious time and effort in presentations or papers (though it must also be said that unless a critical mass of students enrolls for credit, the seminar may be canceled). You can get the syllabus and do the reading independently. You can also get the syllabus, update it, and teach the seminar yourself once you are in a faculty post.
Do not take courses in a vain attempt to learn everything there is to be learned before you take your degree. There is always something new to be learned, and to be a scholar is to be engaged in a lifelong process of learning. And do not take courses as a way of avoiding research. The bottom line is that you should enroll for just enough courses to fulfill the Department and area requirements, plus any additional courses that really stimulate your intellectual interests, and then fill out the remainder of your dance card with research units.
Should I take courses for a grade?
The angel on your right shoulder says "no", on the grounds that you will not be asked to show your transcript when you apply for positions in academe or industry. Moreover, taking courses satisfactory / unsatisfactory (S/U; a grade of S is the equivalent of a B- or better) cuts through the tendency toward grade competitiveness that you may have brought with you from undergraduate school. You are here to learn, not to accumulate A’s. Faculty generally prefer just to work with students, teaching them and learning with them, without grades hanging over our collective heads.
But the fact of the matter is that there is a devil on your left shoulder. That is to say, you may well be asked to present a transcript at some point, if you should apply for certain pre-doctoral or post-doctoral fellowships or internships (e.g., NSF, NIH). It is a sad fact of life that, in the review process for these fellowships, applicants who have taken their courses P/F or S/U are at a competitive disadvantage over those who have taken the same courses and earned A’s.
Moreover, the Graduate Division limits courses taken S/U to 1/3 of the total units a student has taken at Berkeley for their degree. This count excludes courses numbered 299, 300-399, 400-499, and 600-699. (The Graduate Student Handbook has a list of additional courses that are excluding from the 1/3 calculation.) So, the advice from us is to take the required proseminars, statistics, and other required courses and seminars for a grade, so that you will satisfy the University requirement, and also have a transcript that will help you with fellowship and internship applications.
How do I enroll in courses?
Enrolling in courses is quick and easy. All you need is Web access, your Calnet ID and passphrase, and course control numbers (CCN). Each course has a course control number, which is available in the Online Schedule of Classes. The CCN for Psychology 299 (Research) are not in the online schedule but are available on the Psychology Graduate Students bCourses site/Resources/Registration & Enrollment; for CCN for Psychology 298 (Directed Study), please contact the Department’s Scheduling Coordinator. Be sure to do this for every semester you enroll in Psychology 298 or 299, as each faculty member’s CCN changes each semester.
Once you have the CCN you need, log on to CalCentral, Berkeley’s online enrollment system, with your CalNet ID and passphrase. Enter your PIN and select your courses (a total of 12 units is standard). In the summer, a course load of 3 or 4 units is the norm.