<p>I was just thinking about this now. How would a college know you visited their campus?</p>
<p>I know to some colleges interest is important, but how do they see that interest if they can't prove that you visited their campus?</p>
<p>Generally people sign up for tours/information sessions. If you go spontaneously you could probably stop by the admissions office and let them know you are a drop-in.</p>
<p>Colleges know because you usually have to register in advance for the information session and tour. Additionally, when the student arrives he/she signs in.</p>
<p>… in most cases, register in advance does not mean you need an appointment to visit (though it’s never a bad idea to check). Typically when you get to the admissions office, there is some sign in procedure (often a card or form to fill out).</p>