Problem 15 (3 pts): According to materials covered in the class, what are the key to an effective GUI design? Ans: Problem 16 (3 pts): The goal of HCI is to achieve several objectives. In the space below. list 3 of them Problem 17 (3 pts): According to materials covered in the class, there are several design principles that are derived from the HCI fundamentals. In the space below, list 3 of them. Ans