President Maithripala Sirisena says the teacher should mediate to build a disciplined student who is academically as well as ethically enriched.The President, addressing a ceremony held at the Sri Lanka Foundation, today (02) to award Graduate Teaching Appointments in the Western Province, said that teachers are the most important factor when determining the future of a child, and when taking decisions regarding the children those assessments must be taken with a broad understanding and with humanity.