Evaluate an institution's claims offering degrees which can be earned in unusually short periods of time. Earning a degree takes time and hard work. If it seems to easy to earn a degree in a year or two you may have identified a diploma mill.
Check to see if the accreditation credentials are legitimate. Research the accreditation agencies listed. A diploma mill will not have proper accreditations.
Pay attention to offerings of course credit for real life experience. A valid institution will require a lot of well documented information. Demanding little or no documentation to substantiate a student's experience may be a sign that the institution is a diploma mill.
Research the fees charged. Charging fees "per degree" is an indication of a diploma mill. Accredited institutions charge tuition by credit hour, semester or course.
Determine how much interaction with professors is offered. If a student has little or no interaction with professors or teaching assistants, you may have identified a diploma mill.
Look for names that are similar to names of accredited institutions. Diploma mills often adopt a name that is similar to a legitimate institution to confuse students and potential employers.
Check for a legitimate address. A diploma mill often times does not have a real campus and if the address is a post office box, a student should examine the school closely.