Three letters of recommendation coming from persons who know your current academic qualifications are required. Recommenders should be chosen from individuals most familiar with your previous studies, research interests, or maybe work, including at least one trainer in the institution you final attended. The Graduate College prefers recommendations from teachers familiar with your work in the area in which you expect to study.
If you are out of school for some time, some sort of letter from an employer as well as supervisor should be provided. Exclusion to the policy of 3 letters of recommendation is as follows: (1) the advanced certificate put in Ergonomics requires two recommendations, but they are not asked to create letters of recommendation.