DREAM COLLEGE: If you have the finances, this is where you want to attend. What makes this your "DREAM"? Small campus? Large campus? Choice of major? Distance from home? Campus organizations?
REACH COLLEGE: With your GPA and ACT score, this is a place you can get accepted. You see potential in this place and know that, with a little effort and some extra funding by way of scholarships, you can be successful here. Reasons to attend here: Student-to-teacher ratio? Opportunity to become involved? Graduation rates? Distance from home? Familiarity with campus?
SAFE COLLEGE: OK. So your GPA is not the best, or your ACT isn't as high as you would like it to be. Select 1 or 2 "Safe" colleges where you know you will be accepted and should have/can find funding for your dreams. Another reason to choose a "SAFE COLLEGE" is the financial aid package you will receive. $$$$ matters, so having options is important. These may be 4 year colleges you have visited and would consider "a good fit" or junior colleges where you can take core classes before transferring to a school with your major.
