Condolence: I was saddened (and surprised) to learn of Bill's death. Saddened because Bill had been a leading and valued member of the mathematics education community for several decades. I first met Bill in the early 1970s when he was a young assistant professor at the University of New Hampshire and I was an assistant prof at IU. We worked together on various federally-funded research projects. He was always thoughtful and very personable. I was surprised to learn of his passing because I had no idea that he had moved to Bloomington after his retirement. Had I known, I'm sure we'd have enjoyed spending time together in our retirement. Bill lived a full, rewarding life. We are all better people for having known him! My condolences go out to his family.