Blackboard's SafeAssign compares student submissions to a large database of essays and uses an algorithm to identify possible instances of plagiarism. When you create an assignment in Bb, you have the option of turning on SafeAssign. Directions:
Click Assessments >> Assignment
Under "Grading" click Submissions Details and check "Check Check submissions for plagiarism using SafeAssign". We also recommend checking "Allow students to view SafeAssign originality report for their attempts"