I think it depends on what type of research you're doing. If you're doing clinical type, more of patient interaction, questionare, survey analysis kinda of research, which doesn't take much time and extremely flexible, you'll be fine. You can do those work at home, on a computer, and the time you spend in the clinic is flexible too. But if you're talking about pure science, working in a lab, it's gonna be tough. A few of my classmates are doing it. They get paid to do around 5 hrs a week. I didn't have any special training, and tried to work in a oral biology lab. My mentor expects me to do at least 10 hrs a week, and it has to be during the week days because they can't let me come in to the lab alone on the weekends. Besides labwork, I'm expected to develop my own project, have ideas how to approach it, and lots of progress reports, presentations. But again, I'm a first year, with minimum research experience. It's not easy for me, and I'm single 😛