When students apply for a PhD program, their background and preparation for the PhD is considered mainly via the range of course work and performance in those courses. Letters of recommendation are also vital. However one thing which may make the biggest difference is demonstrating actual research experience. This can be
- an impressive senior year project with some original research
- a suitable project or survey in an advanced and directly relevant course
- a summer working as an intern in an established research lab
- research assistantship with an established researcher in the field
- a research paper (even if it is in some student publication)
- assisting in some large collaborative research project
The idea is that admission committees prefer candidates who have some idea about the well-motivated problems in the research area and have the maturity to formulate a research problem and come up with the ideas to solve the problem. These abilities are demonstrated more easily by actual research than course work. For example, any relevant preliminary research already indicates the research interests, writing skills and technical skills of a candidate. Such research is also a useful exercise for the applicant to get a feel of what kind of research they are interested in.
Familiarity with a research area can also be demonstrated by attending workshops and tutorials designed for pre-doctoral or doctoral students and going to relevant seminars. Similarly, one learns many useful things if one has already some research experience during the undergraduate years. One specially learns a lot by collaborating with more senior researchers. This makes the transition into a PhD program easier.