@cappex : You are right for Emory and the engineering comment, but other schools with actual engineering programs and departments that are very selective do indeed tend to have a bias towards those with experience, likely due to the intensity of those curricula and the number of course requirements/inflexibility. With experienced students, they can decrease the likelihood of attrition (those students can transition into college level engineering more easily without intro. and intermediate courses needing to be doused in water). For Emory, demonstrating competence in science is all that is needed to be competitive I would think because ultimately it is a science track.