A popular Iowa State University professor known for his challenging assignments is retiring. Bill Boon’s “Creativity 129” asked students to think “outside the box” with assignments such as building a pumpkin launcher. Boon says he got the idea for the wacky assignments from a couple of fellow educators on the West Coast.They encouraged him to do things that were media-oriented and would draw a lot of attention. The first assignment was to launch a water balloon at him from 25 feet away. Students that hit Boon got an “A”. Boon says his wildest assignment was asking students to come to class without clothes.He wanted students to think beyond the first answer to the problem, which was come to class naked. Boon says students came to that class dress in clothes made of cards, license plates, toilet paper and various other materials. He says that assignment do draw a lot of attention and helped make the class more interesting.After 25 years of teaching, will Boon miss the classroom? He says he probably will, but says probably not for awhile as it takes a lot of work to get things ready.Boon’s final class assignment was to build 15-foot characters that could walk in this past weekend’s homecoming parade.