COMMUNICATIONS CACM.ACM.ORG OF THEACM 09/2013 VOL.56 NO.09 Uncomfortable User Experience Association for Computing Machinery COMMUNICATIONS OF THE ACM Departments News Viewpoints 5 Editor’s Letter 28 Law and Technology Has The Innovation Cup Run Dry? What to Do About Google? By Moshe Y. Vardi Whether it is acting as a conduit, an editor, or an advisor, the search 7 From the President engine should put user interests first. Freedom and the Social Contract By James Grimmelmann By Vinton G. Cerf 31 Historical Reflections 8 Letters to the Editor Software and Souls; For Privacy and Security, Programs and Packages Use Public Keys Everywhere How can historians tell stories about software without focusing 10 BLOG@CACM solely on the code itself? Big Data Is ‘Buzzword du Jour;’ By Thomas Haigh CS Academics ‘Have the Best Job’ 13 Michael Stonebraker analyzes 35 The Profession of IT the different varieties of Big Data, 13 Magnetic Diversion The Other Side of Language while Judy Robertson for Electronic Switches The conversation for action gives considers the rewards of ‘Chameleon processors’ could a framework for completing teaching computer science. function as programmable logic professional actions effectively. or nonvolatile memory. By Peter J. Denning 43 Calendar By Chris Edwards 38 Viewpoint 107 Careers 16 Software-Defined Networking Research and Practice: Novel architecture allows The Curious Case of ‘Small’ programmers to quickly reconfigure Researchers-Practitioners Last Byte network resource usage. Seeking a more efficient combination By Keith Kirkpatrick of the best elements of the research 110 Puzzled Answers and practice communities in Solutions and Sources 20 Ephemeral Data small organizations. By Peter Winkler Privacy issues can evaporate when By Željko Obrenovi´c embarrassing content does likewise. 112 Q&A By Esther Shein 41 Interview Big Challenge An Interview with Hadi Partovi Jeff Dean and Sanjay Ghemawat 24 Remembering Douglas Engelbart The Code.org founder discusses talk about scalability. By Laura DiDio his first program, inspirations, By Leah Hoffmann and “seizing the day.” By Lawrence Snyder H BY JOAN CHANG JOAN H BY P Association for Computing Machinery Advancing Computing as a Science & Profession PHOTOGRA 2 COMMUNICATIONS OF THE ACM | SEPTEMBER 2013 | VOL. 56 | NO. 9 09/2013 VOL. 56 NO. 09 Practice Contributed Articles Review Articles 54 66 84 46 The Balancing Act of Choosing 66 Uncomfortable User Experience 84 Verifying Autonomous Systems Nonblocking Features How to create and resolve Exploring autonomous systems Design requirements discomfort for a thrilling and and the agents that control them. of nonblocking systems. memorable experience. By Michael Fisher, Louise Dennis, By Maged M. Michael By Steve Benford, Chris Greenhalgh, and Matt Webster Gabriella Giannachi, Brendan Walker, 54 20 Obstacles to Scalability Joe Marshall, and Tom Rodden S Watch out for these pitfalls that Research Highlights ATE CI can prevent Web application scaling. 74 Computing with Real Numbers, O Ass By Sean Hull from Archimedes to Turing 96 Technical Perspective S ORY and Beyond Progress in Visual Categorization B IJ R 59 An Overview of Non-Uniform How to test the usefulness By Pietro Perona D N A Memory Access of computation for TA/ IS NUMA becomes more common understanding and predicting 97 Visual Object Detection with UB K A because memory controllers continuous phenomena. Deformable Part Models ICI L get close to execution units By Mark Braverman By Pedro Felzenszwalb, Ross Girshick, A on microprocessors. David McAllester, and Deva Ramanan ON BY ON BY I By Christoph Lameter TRAT S ; ILLU Articles’ development led by D queue.acm.org ARRY DOWNAR ARRY B ON BY ON BY I About the Cover: TRAT While art and cinema S have long been known for LLU I exploring ways to make the viewer feel anxious or frightened, this month’s OM; PHOTO OM; PHOTO cover story (p. 66) focuses C K. on the benefits of designing C TO computer games, apps, S amusement rides, and other online experiences with the deliberate purpose of making the user feel uncomfortable. Cover photo illustration by Barry IMAGE FROM SHUTTER IMAGE Downard. SEPTEMBER 2013 | VOL. 56 | NO. 9 | COMMUNICATIONS OF THE ACM 3 COMMUNICATIONS OF THE ACM Trusted insights for computing’s leading professionals. Communications of the ACM is the leading monthly print and online magazine for the computing and information technology fields. 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