Why does ALEKS use personal student subscriptions?

ALEKS is an individualized, self-paced mathematics learning system.  Because each student account in ALEKS contains specific data regarding that student's course progression, Knowledge Check data, assignment grades, and other private information, each student account has a specific subscription assigned to it.  These accounts and their subscriptions are not considered transferable.  Having another student use an existing student's account will not only cause issues in the future in determining what data belongs to what student but the original student's progress will most likely not be in line with what the new student knows.  This will cause ALEKS to offer the student questions that are either too complex or too simple for them, given their current level of knowledge, and would create a frustrating, negative, experience for the student.