Do residency programs usually prefer students with publications in journals or are students that only have poster presentations given equal consideration?
As you would imagine this is a topic that will vary from region to region and program to program. Some that are research-oriented may favor actual publications more than presentations, etc... At the end of the day, however, this will be but one component of the overall picture - most people are well aware that medical students have very little "pull" in actually getting a project published so if it does get published it's pretty remarkable.