The Callahan Theory is performed when a person completes all of his/her homework on the absolute last day of the semester. No homework is done through out the course until the last day. Then, he/she hands all of it in to the teacher all at once. To complete the theory, you must still achieve a 3.5 GPA.
Matt - "Hey Pat, have you done your homework tonight?"
Pat - "No, we're only two weeks into the course, I follow the Callahan Theory."
Matt - "What's that?"
Pat - "It's when I do all of my homework on the last day of the semester, and still get an A!"
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