Just sending Emails, UH evaluated students, then based on their GPA, being international, being full-time, and any available previous employment records at UH made the decision.At the and they send us approval letter.

Actually graduate teaching and research assistants are assigned by their academic advisers (professors). If the professor is satisfied with your knowledge and background in his or her field of study, he or she will assign you as a teaching or research assistant. so each professor may interview the student in their own way.