Professor Liu is an educator in the truest sense of the word. He is a highly regarded author of computer science textbooks, a superb teacher, inside and outside the classroom, and has contributed significantly to computer science educational programs at both the national and international levels.

In 1968 Professor Liu's book on combinatorial mathematics served as a pioneering effort in bringing this important branch of mathematics into the computer science curriculum. It convincingly demonstrated that combinatorial mathematics was both useful to a computer scientist as well as exciting, challenging and teachable at the undergraduate level. His 1977 book on discrete mathematics emphasized computer science applications and has undoubtedly influence books on this subject published since that time.

Professor Liu is a dynamic lecturer, full of energy and humor, skillful in presenting difficult material and responsive to students' needs. His excellence at the undergraduate level has been recognized by several teaching awards. His list of Ph.D. students supervised is impressive. He has helped establish curriculum standards at the national and international levels. He is admired and respected for his total devotion to teaching and distinguished leadership in education.