The University of Northern Iowa is offering a new reward for teachers willing to work with U-N-I student teachers. College of Education Dean Thomas Switzer says the school will offer certificates of value to master teachers. He says the certificates may be applied to one graduate hour of credit at U-N-I, currently valued at 206-dollars. He says it will allow them to take any course at the university for professional growth and development.Switzer says each year about 12-hundred teachers cooperate by allowing student teachers to train in their classrooms.Each certificate is good for three years after the date it is issued.