Shneiderman's cognitive analysis of user needs led to principles of direct manipulation interface design in 1982: (1) continuous representation of the objects and actions, (2) rapid, incremental, and reversible actions, and (3) physical actions and gestures to replace typed commands, which enabled designers to craft more effective graphical user interfaces. He applied those principles to design innovative user interfaces such as the highlighted selectable phrases in text, that were used in the commercially successful Hyperties. Hyperties was used to author the world's first electronic scientific journal issue, which was the July 1988 issue of the "Communications of the ACM" with seven papers from the 1987 Hypertext conference. It was made available as a floppy disk accompanying the printed journal. Tim Berners-Lee cited this disk as the source for his "hot spots" in his Spring 1989 manifesto for the World Wide Web. Hyperties was also used to create the world's first commercial electronic book, "Hypertext Hands-On!" in 1988.