My group has reached the point where our lab is (mostly) set up and everyone is making some progress on their projects. Meetings are much more fun now, with new data to talk about nearly all the time. One of my grad students is doing extremely well--she is thinking up new experiments, figuring out how to test out ideas, bringing in new literature to think about, and generally owning her project. Some of this is of course very raw, but I can see how she is starting to think scientifically and creatively.
My other grad student is making good progress on data acquisition (which is of course important), but still needs a lot more guidance. He only does experiments we have discussed in detail before hand, and never does any kind of follow up (beyond rudimentary data analysis) on his own. He is happy to go ahead and do more, but only after I tell him what to do next. I find myself sending him papers on his project (which is normal), but he never looks to see how they have been cited, unless directed to specifically (which I've done many times). He isn't lazy by any means, just not very independent. I know he has only been in the group a year, but my summer students seem more independent (if less experienced) than he does.
I am thinking about my approach to mentoring--I have a fairly hands off approach that seems to be working well with 4 of my 5 lab peeps. I talk to everyone at least once a day informally, and walk through the lab a few times in case people want to talk. Maybe this student needs some more structure? Some more limited independent projects to try on before tackling his PhD project? I know that not all approaches work for all people, and I don't want this student to fall through the cracks through my own failure, since he is smart, interested in science, and a hard worker. My own experiences are not a good guide, since both my PhD advisor and my postdoc advisor were extremely hands off (more even than I am!).