Today's comment was prompted by a discussion of how a student's graduate committee functions. In my previous department, grad students were supposed to meet with their committee every semester to review their progress. Initially, it was a bit scary, but I've really warmed to the idea. Yes, part of the reason the committee would meet was to make sure everyone was making adequate progress in their program. Yes, you could get axed if you weren't making progress. However, there were a lot of benefits to this system that became clear after it was instituted. First, you are far less likely to run into the random committee member who simply can't believe you didn't use method XYZ in your thesis. (Don't forget the comments about how could you possibly call this work science/engineering without it????) Meeting regularly ensured the committee was on the same page as the student. It also ended up being rather productive. If you were stuck on a problem that your advisor wasn't necessarily able to help with, sometimes other committee members could jump in with suggestions. Finally, if you had a good committee, it would make sure that the program was working for the student. Advisors couldn't be unscrupulous and demand that students work an insane amount in order to get their degree. The committee wanted to make sure students were graduating in a timely matter while also checking to make sure the work was appropriate for the degree.
Originally, I think it was instituted to 'scare' people into keeping on task in their research and/or provide a mechanism to remove students who obviously had no interest in the program. What I don't think anyone realized until it started was that, by meeting regularly, it helped people to make progress because it was helpful and reduced the need to scare (most) students into working. Sometimes students languish longer than necessary because they are stuck and/or don't feel like they're going down the right track.
I generally left these meetings feeling like they had been a good use of time. More often than not, they were actually encouraging. When you hear that your professors are happy with your progress or have useful suggestions on how to approach things, it's a good feeling and can do a lot to lift morale.
When my husband was doing his PhD (maybe he'll elaborate more on this if he is so inclined), he ended up hitting a major roadblock with his first research track. He ended up switching to a slightly related topic, only to end up getting scooped. Finally, he had a bullet-proof topic, but was having issues on some aspect which involved proving mathematically that his proposed method was valid. The regular meetings were established while he was in the middle of his program. They started after the switching from the initial topic and the scooping incident. After they started, it seemed like he was able to progress a bit faster and ended up getting a suggestion on his math proof that ended up being a major aspect of his dissertation. I have wondered what would have happened if he'd been meeting with his committee all along.
In my current department, I was told that after you finish your orals, you may not see your committee members again (in a formal function) until your defense. I do realize that this is probably the norm (or so I have heard from a lot of other people). After having been through this other system, however, I find this very disappointing. Admittedly, your advisor should be guiding your research, but wouldn't feedback and input from other colleagues be useful while going through the process? Wouldn't it be helpful for committee members to follow a student's progress rather than being handed a huge document at the end of a few years which may or may not be up to their standards? I find this a particularly important question given these same people will have to decide if your work really is good enough to give you a degree. Most science and engineering is not done in a vacuum, and yet it seems like most committee members may come into a defense not having a clue what changes have made or what the student has gone through. (This is especially true if you have a committee member from another department, or as I did, from another school.) If they had useful suggestions on the process, getting them at the point of completion isn't terribly helpful.