clear manner to enable cooperation Explain processes to support education and training Predict performance in normal and novel situations so as to increase the chances of success Prescribe guidelines, recommend best practices, and caution about dangers Generate novel ideas to improve research and practice. These goals are frequently taught in courses on Human-Computer Interaction and cited in works by authors such as Yvonne Rogers, Victor Kaptelinin, and Bonnie Nardi. Direct manipulation interface 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. Direct manipulation concepts led to touchscreen interfaces for home controls, finger-painting, and the now ubiquitous small touchscreen keyboards. The development of the "Lift-off strategy" by University of Maryland Human–Computer Interaction Lab (HCIL) researchers enabled users to touch the screen, getting feedback as to what will be selected, adjust their finger position, and complete the selection by lifting the finger off the screen. The HCIL team applied direct manipulation principles for touchscreen home automation systems, finger-painting programs, and the double-box range sliders that gained prominence by their inclusion in Spotfire. The visual presentation inherent in direct manipulation emphasized the opportunity for information visualization. In 1997, Pattie Maes and Shneiderman had a public debate on Direct Manipulation vs. Interface Agents at CHI'97 and IUI 1997 (with the IUI Proceedings showing two separate papers but no remaining internet trace of the panel.) Those events helped define the two current dominant themes in human-computer interaction: direct human control of computer operations via visual user interfaces vs delegation of control to interface agents that know the