Participating in research can help you decide whether a PhD is right for you and, if you do apply, makes you a stronger applicant.
If you are looking for a short-term research experience, consider a paid summer internship organized by GSAS, Harvard departments, and Harvard-affiliated teaching hospitals. GSAS also offers a post-baccalaureate program, called the Research Scholar Initiative, which enables college graduates to take part in a long-term research experience.