William Foote Whyte, a sociology professor known for his work with urban gangs, died July 16. He was eighty-six. A 1936 graduate of Swarthmore, he earned a PhD in sociology from the University of Chicago. He began teaching on the Hill in 1948 as one of the first ILR professors. The title of his autobiography, Participant Observer, reflects his approach to academia--that a researcher can be a positive force for social change. "If there is a common theme in my work, it is my commitment to social exploration," he wrote. "Fieldwork fascinates me. I want to explain what is out there."Whyte, who became an emeritus professor in 1979, published twenty books, including the ground-breaking Street Corner Society, a 1943 study of Italian gangs in Boston's North End. He is survived by his wife of sixty-two years, Kathleen King Whyte, four children, twelve grandchildren, and eight great-grandchildren.