From UT Dallas Judicial Affairs:

In class or out-of-class academic exercises are representations of a student's individual aptitude and scholarly achievement. Each student is expected to exercise independent scholarly thought, expression and aptitude. While there is much to be gained through a well-functioning study group, participating in an act of collusion will prove detrimental. Absent specific authorization from the course instructor, each academic exercise is presumed to be prepared and submitted by one student acting individually and not in concert with others.

Acts of collusion can be purposeful or unintentional. Common examples are:

• two students in the same class submitting a substantially similar essay, homework or computer program assignment
• one student providing another with a copy of a completed assignment, only to have the assignment duplicated and submitted for credit with a new name
• study or lab partners submitting duplicate solution reports