Misplaced Pages

Revision as of 22:01, 6 January 2009

Carl E. Hewitt is Associate Professor Emeritus in the Electrical Engineering and Computer Science department at the Massachusetts Institute of Technology (MIT).

Hewitt is known for his design of Planner, which was the first programming language based on procedural plans that were invoked using pattern-directed invocation from assertions and goals, and was influential in the development of both logic programming and object-oriented programming. He is also known for his work on the Actor model of concurrent computation, which influenced the development of the Scheme programming language and the π calculus, and served as an inspiration for several other programming languages. His publications also include contributions in the areas of open information systems, multi-agent systems, logic programming, , concurrent programming languages, paraconsistent logic, cloud computing . Hewitt's Erdős number is 3 (by two different co-authors).

Education

Hewitt obtained his PhD in mathematics at MIT in 1971, under the supervision of Seymour Papert, Marvin Minsky, and Mike Paterson.

Work on Planner

The Planner language was developed during the late 1960s as part of Hewitt's doctoral research in MIT's Artificial Intelligence Laboratory. Hewitt's work on Planner introduced the notion of the "procedural embedding of knowledge", which was an alternative to the logical approach to knowledge encoding for artificial intelligence pioneered by John McCarthy. Planner has been described as "extremely ambitious". A subset of Planner called Micro-Planner was implemented at MIT by Gerry Sussman, Drew McDermott, Eugene Charniak and Terry Winograd, and was used in Winograd's famous SHRDLU program, Charniak's natural language story understanding work, and L. Thorne McCarty's work on legal reasoning. Planner was almost completely implemented in Popler by Julian Davies at Edinburgh, where (together with earlier work at Edinburgh on Pico-Planner by Bruce Anderson) it influenced Robert Kowalski and Pat Hayes in the development of ideas that later became Prolog. Planner also influenced the later development of other AI research languages such as Muddle, Micro-Planner, and Conniver, as well as the Smalltalk object-oriented programming language.

Hewitt's own work on Planner continued with Muddle (later called MDL), which was developed in the early 1970s by Sussman, Hewitt, Chris Reeve, and David Cressey as a stepping-stone towards a full implementation of Planner. Muddle was implemented as an extended version of Lisp, and introduced several features that were later adopted by Conniver, Lisp Machine Lisp, and Common Lisp. However, in late 1972 Hewitt abruptly halted his development of the Planner design in his thesis, when he and his graduate students invented the Actor model of computation.

Work on the Actor model

Hewitt's work on the Actor model of computation has spanned over 30 years, beginning with the introduction of the model in a 1973 paper authored by Hewitt, Peter Bishop, and Richard Steiger, and including new results on Actor model semantics published as recently as 2006. Much of this work was carried out in collaboration with students in Hewitt's Message Passing Semantics Group at MIT's Artificial Intelligence Lab.

The Actor model was the original inspiration for Sussman and Steele's work on the Scheme programming language, and also provided the motivation for the development of a number of languages specifically intended to implement the Actor model, such as ACT-1, SALSA, Caltrop,, E and ActorScript.

Work on privacy-friendly client cloud computing

Hewitt's recent work has centered on foundations for privacy-friendly client cloud computing. This approach to cloud computing focuses on clients that are "privacy-friendly" because of the following

• by default clients store information in the cloud that can only be unencrypted using the client's private key
• semantic integration of diverse sorts of information (calendar, email, contacts, documents, search results, presence information, etc.) is performed on the clients

This work has resulted in the following developments:

• strongly paraconsistent logic using Direct Logic to more safely reason about pervasively inconsistent information
• concurrent reasoning using ActorScript

MIT career

He retired from the faculty of the MIT Department of Electrical Engineering and Computer Science during the 1999-2000 school year. Among the doctoral students that Hewitt supervised during his time at MIT are Professor Gul Agha, Dr. Russell Atkinson, Dr. Henry Baker, Dr. Gerald Barber, Dr. Peter Bishop, Dr. Gene Ciccarelli, Professor William Clinger, Dr. Peter de Jong, Dr. Michael Freiling, Dr. Irene Greif, Dr. Kenneth Kahn, Dr. William Kornfeld and Professor Akinori Yonezawa.

Awards

From September 1989 to August 1990, Hewitt was the IBM Chair Visiting Professor in the Department of Computer Science at Keio University in Japan.

Observer attack on Hewitt and his response

In late 2007, The Observer reported that Hewitt "has been banned from editing the online collaborative encyclopaedia Misplaced Pages." The article stated

Hewitt "is alleged to have disrupted Misplaced Pages for more than two years by using it for self-promotion, tampering with his own biography and manipulating computer science articles to inflate the importance of his own research. Senior academics in his field say the changes he made have rendered some entries in effect useless."

In contrast, Hewitt published an article on Google Knol that is highly critical of Misplaced Pages citing "corruption" of its administration. Hewitt commented as follows on the Observer article:

"A recent example of Misplaced Pages libel occurred when I became involved in an academic dispute with Robert Kowalski over a Computer Science research area called “Logic Programming.” Kowalski appealed to an Administrator of Misplaced Pages to intervene in the dispute (see the discussion in the appendix of Corruption of Misplaced Pages). Thus Kowalski was in effect promoting his own side of an academic dispute by participating in my censorship by Misplaced Pages. (See Middle History of Logic Programming for a detailed discussion of the dispute.)

Although lacking expertise in this particular area of Computer Science, Charles Matthews (a very high level Misplaced Pages official) favored Kowalski’s side and using his Misplaced Pages power enforced it by censorship with the justification of “Neutral Point of View.” Furthermore, Matthews “tipped off” a reporter (who he had successfully “cultivated” to write stories favorable to Misplaced Pages) to enlist her in writing an article that libeled me. Matthews then became the principle unnamed source for the resulting Observer hatchet job appearing under the false guise of an independent “senior academic” in my field of research casting aspersions on me. While he was angry with me because of our academic dispute, Kowalski confided in Matthews. As a result, Matthews sent the reporter off to interview Kowalski. Consequently, the reporter has tape recordings and emails of Kowalski saying some things in anger about me. (Kowalski has subsequently made amends in his emails to me; see below.)

As part of its business model, Misplaced Pages engages in libel and vilification in an attempt to intimidate people into conforming to censorship by its Administrators." (emphasis in original)

Selected works

• Carl Hewitt (1969). PLANNER: A Language for Proving Theorems in Robots IJCAI'69.
• Carl Hewitt, Peter Bishop and Richard Steiger (1973). A Universal Modular Actor Formalism for Artificial Intelligence IJCAI'73.
• Carl Hewitt and Henry Baker (1977a). Laws for Communicating Parallel Processes IFIP'77.
• Carl Hewitt and Henry Baker (1977b). Actors and Continuous Functionals Proceeding of IFIP Working Conference on Formal Description of Programming Concepts. August 1–5, 1977.
• William Kornfeld and Carl Hewitt (1981). The Scientific Community Metaphor IEEE Transactions on Systems, Man, and Cybernetics. January 1981.
• Henry Lieberman and Carl E. Hewitt (1983). A Real-Time Garbage Collector Based on the Lifetimes of Objects Communications of the ACM, 26(6).
• Carl Hewitt (1985). The Challenge of Open Systems Byte Magazine. April 1985. (Reprinted in The foundation of artificial intelligence--a sourcebook Cambridge University Press. 1990)

See also

• Scientific community metaphor

References

1. "EECS Department Faculty", MIT, accessed November 12, 2007.
2. ^ Carl Hewitt. PLANNER: A Language for Proving Theorems in Robots IJCAI. 1969.
3. Filman, Robert (1984). "Actors". Coordinated Computing - Tools and Techniques for Distributed Software. McGraw-Hill. p. 145. ISBN 0-07-022439-0. Carl Hewitt and his colleagues at M.I.T. are developing the Actor model. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
4. Krishnamurthi, Shriram (1994). "An Introduction to Scheme". Crossroads. 1 (2). {{cite journal}}: Unknown parameter |month= ignored (help)
5. Milner, Robin (1993). "ACM Turing Award Lecture: The Elements of Interaction" (PDF). Communications of the ACM. 36 (1). {{cite journal}}: Unknown parameter |month= ignored (help)
6. ^ Mark S. Miller (2006). "Robust Composition - Towards a Unified Approach to Access Control and Concurrency Control" (PDF). PhD dissertation. Johns Hopkins University. Retrieved 2007-05-26. {{cite journal}}: Cite journal requires |journal= (help)
7. Carl Hewitt (1986). "Offices Are Open Systems". ACM Trans. Inf. Syst. 4(3): 271-287. {{cite journal}}: Cite journal requires |journal= (help)
8. Jacques Ferber (1999). Multi-Agent Systems: An Introduction to Distributed Artificial Intelligence. Addison-Wesley.
9. Hewitt, Carl (2008), "Development of Logic Programming: What went wrong, What was done about it, and What it might mean for the future", in Goker, Mehmet; Shapiro, Daniel (eds.), What Went Wrong and Why: Lessons from AI Research and Applications, AAAI Press
10. ^ Hewitt, Carl. "Common sense for concurrency and strong paraconsistency using unstratified inference and reflection". ArXiv. December 30, 2008.
11. Hewitt, Carl (2008), "Large-scale Organizational Computing requires Unstratified Reflection and Strong Paraconsistency", in Sichman, Jaime; Noriega, Pablo; Padget, Julian; Ossowski, Sascha (eds.), Coordination, Organizations, Institutions, and Norms in Agent Systems III, Springer-Verlag
12. Carl Hewitt (September/October 2008). "ORGs for Scalable, Robust, Privacy-Friendly Client Cloud Computing". IEEE Internet Computing. 12 (5). {{cite journal}}: Check date values in: |date= (help)
13. Carl Hewitt. "A historical perspective on developing foundations for privacy-friendly client cloud computing". Retrieved 2008-10-19.
14. Carl Hewitt. Procedural Embedding of Knowledge In Planner IJCAI. 1971.
15. Philippe Rouchy, Aspects of PROLOG History: Logic Programming and Professional Dynamics, TeamEthno-Online Issue 2, June 2006, 85-100.
16. ^ Sussman, Gerald Jay (1998). "The First Report on Scheme Revisited" (PDF). Higher-Order and Symbolic Computation. 11. Boston: Kluwer Academic Publishers: 399–404. Retrieved 2009-01-03. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
17. Gerry Sussman and Terry Winograd. Micro-planner Reference Manual AI Memo No, 203, MIT Project MAC, July 1970.
18. Terry Winograd. Procedures as a Representation for Data in a Computer Program for Understanding Natural Language MIT AI TR-235. January 1971.
19. Marvin Minsky and Seymour Papert. “Progress Report on Artificial Intelligence” MIT AI Memo 252. 1971.
20. L. Thorne McCarty. "Reflections on TAXMAN: An Experiment on Artificial Intelligence and Legal Reasoning" Harvard Law Review. Vol. 90, No. 5, March 1977
21. Julian Davies. Popler 1.6 Reference Manual University of Edinburgh, TPU Report No. 1, May 1973.
22. Bruce Anderson. Documentation for LIB PICO-PLANNER School of Artificial Intelligence, Edinburgh University. 1972.
23. [http://knol.google.com/k/carl-hewitt-httpcarlhewittinfo/middle-history-of-logic-programming/pcxtp4rx7g1t/3# Middle History of Logic Programming Resolution, Planner, Prolog and the Japanese Fifth Generation Project]
24. Kay, Alan (2003-07-23). "E-Mail of 2003-07-23". Dr. Alan Kay on the Meaning of “Object-Oriented Programming”. Retrieved 2009-01-03. {{cite web}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
25. Carl Hewitt (1973). "A Universal Modular Actor Formalism for Artificial Intelligence". IJCAI. {{cite journal}}: Cite journal requires |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
26. Carl Hewitt What is Commitment? Physical, Organizational, and Social COIN@AAMAS. April 27, 2006.
27. Mark S. Miller. "Actors: Foundations for Open Systems". Retrieved 2007-06-20.
28. Gerald Sussman and Guy Steele SCHEME: An Interpreter for Extended Lambda Calculus AI Memo 349, MIT Artificial Intelligence Laboratory, Cambridge, Massachusetts, December 1975
29. Henry Lieberman, "Concurrent Object-Oriented Programming in Act 1", In Object-Oriented Concurrent Programming, A. Yonezawa and M. Tokoro, eds., MIT Press, 1987.
30. C. Varela and G. Agha. Programming Dynamically Reconfigurable Open Systems with SALSA. OOPSLA 2001 Intriguing Technology Track. ACM SIGPLAN Notices, 36(12):20-34, December 2001.
31. Johan Eker. "An introduction to the Caltrop actor language" (PDF). Retrieved 2007-06-20. {{cite journal}}: Cite journal requires |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
32. Video recording of "Scalable Privacy-Friendly Client Cloud Computing: a gathering Perfect Disruption" Stanford Computer Systems Colloquium on October 22, 2008.
33. Carl Hewitt (September/October 2008). "ORGs for Scalable, Robust, Privacy-Friendly Client Cloud Computing". IEEE Internet Computing. 12 (5). {{cite journal}}: Check date values in: |date= (help)
34. Carl Hewitt (January/February 2009). "Perfect Disruption: The Paradigm Shift from Mental Agents to ORGs". 11 (1). {{cite journal}}: Check date values in: |date= (help); Cite journal requires |journal= (help)
35. Carl Hewitt. "A historical perspective on developing foundations for privacy-friendly client cloud computing". Retrieved 2009-1-6. {{cite web}}: Check date values in: |accessdate= (help)
36. John V. Guttag (2000). "MIT Reports to the President 1999–2000 - Department of Electrical Engineering and Computer Science". Retrieved 2007-06-19.
37. Carl Hewitt (2007). "Academic Biography of Carl Hewitt". Retrieved 2007-11-22.
38. Ryuichiro Ohyama (1991). "Department of Computer Science-Recent and Current Visiting Professors". Retrieved 2007-06-19.
39. Kleeman, Jenny (9 December 2007). "Misplaced Pages ban for disruptive professor". The Observer. p. 18.
40. Carl Hewitt (2008). "Corruption of Misplaced Pages". Retrieved 2009-01-04.

External links

• h at DBLP Bibliography Server
• List of publications from Hewitt's web page.
• Carl Hewitt's blog.
• Carl Hewitt's homepage.
• Audio interview with Carl Hewitt conducted by Jon Udell on November 18, 2008.
• Video recording of "Scalable Privacy-Friendly Client Cloud Computing: a gathering Perfect Disruption" Stanford Computer Systems Colloquium on October 22, 2008.
• Video interview with Carl Hewitt on YouTube conducted by Ideas Project on October 28, 2008.

Template:Persondata

• Living people
• American computer programmers
• American computer scientists
• American educators
• American mathematicians
• Formal methods people
• Massachusetts Institute of Technology faculty
• American technology writers