1. Socially Sensitive Computing: A necessary Paradigm Shift for Computer Science Tom Addis Computer Science & Software Engineering University of Portsmouth Bart-Floris Visscher Computer Science & Software Engineering University of Portsmouth Dave Billinge Creative Technology University of Portsmouth “Rules are for the obedience of fools and the guidance of wise men” Douglas Bader (1910 –1982)

2. 30th March 2004GC7 Non-Classical Computing2 Formal Semantics Church-Turing Thesis: Church-Turing Thesis: Equivalent Representation Systems Equivalent Representation Systems Computer program (Turing Machines) Computer program (Turing Machines) Functional Statements (Functional Machines) Functional Statements (Functional Machines) Tractatus Propositions (Predicate Machines) Tractatus Propositions (Predicate Machines) It follows that: It follows that: Everything is potentially unambiguously describable Everything is potentially unambiguously describable All sets are rational (countable) All sets are rational (countable) Set membership is always specifiable and context independent or has an explicit context Set membership is always specifiable and context independent or has an explicit context Fuzzy (ordinal) and probabilistic sets (ratio of integers) are countable Fuzzy (ordinal) and probabilistic sets (ratio of integers) are countable

3. 30th March 2004GC7 Non-Classical Computing3 Consequences of Formal Model Practical Practical Any set of names can be used in a program to represent a proposition. Any set of names can be used in a program to represent a proposition. There is an infinite but bounded set of possible organisations of a program. There is an infinite but bounded set of possible organisations of a program. There is a such a thing as a ‘minimum program’ There is a such a thing as a ‘minimum program’ Programs can only have one interpretation. Programs can only have one interpretation. Social Social Rules can be constructed that can describe unambiguously any situation. Thus: Rules can be constructed that can describe unambiguously any situation. Thus: Rules can bypass human judgement. Rules can bypass human judgement. There is only one correct way to see the world There is only one correct way to see the world

4. 30th March 2004GC7 Non-Classical Computing4 Problem 1 Programs can only have a single interpretation. Programs can only have a single interpretation. But programs have at least two interpretations But programs have at least two interpretations The Computer State The Computer State The Problem Domain The Problem Domain Program Problem Domain Computer States (bits)

5. 30th March 2004GC7 Non-Classical Computing5 Formal Interpretation Mapping onto Wittgenstein’s Objects. Mapping onto Wittgenstein’s Objects. Independent Independent Atomic Atomic Exist in all possible worlds Exist in all possible worlds Immaterial Immaterial Indescribable Indescribable Self governed Self governed The bit has all these properties The bit has all these properties Such objects are rarely in the Problem Domain Such objects are rarely in the Problem Domain Program Computer States (bits) The only rational interpretation of a program

6. 30th March 2004GC7 Non-Classical Computing6 Problem 2 Everything is NOT potentially unambiguously describable Everything is NOT potentially unambiguously describable There are also irrational sets (not countable). There are also irrational sets (not countable). Some sets depend upon human usage and context. Some sets depend upon human usage and context. Examples: Examples: Games, chairs and life Games, chairs and life A Chair Jean-Francois Dupris Chair Specification: Designed specifically to be sat upon, Stands on its own Has four legs Has a back Sitter’s Feet touches floor Chair Specification: Designed specifically to be sat upon Stands on its own Has four legs Has a back Chair Specification: Designed specifically to be sat upon Stands on its own Chair Specification: Designed specifically to be sat upon Chair Specification: Designed to be sat upon Chair Specification:

7. 30th March 2004GC7 Non-Classical Computing7 Current Status of Computer Science We have computer programs with a semantics based upon computer bits. We have computer programs with a semantics based upon computer bits.and We create programs that cannot rationally be assigned meaning to the very problem domain for which we write them. We create programs that cannot rationally be assigned meaning to the very problem domain for which we write them.

8. 30th March 2004GC7 Non-Classical Computing8 Computing with Irrational Sets 1 Programs must remain in the domain of rational sets. Programs must remain in the domain of rational sets. We have the freedom to use the program’s accidental properties: We have the freedom to use the program’s accidental properties: The choice of names The choice of names The choice of program organisation The choice of program organisation The choices are used to provide a semantic link with the problem domain. The choices are used to provide a semantic link with the problem domain.

9. 30th March 2004GC7 Non-Classical Computing9 Practical Consequences Choice of program names and organisations must be flexible. Choice of program names and organisations must be flexible. The dynamics of program names, organisations and assignment of meaning must be linked to a social system. The dynamics of program names, organisations and assignment of meaning must be linked to a social system. A method for a ‘minimum program’ is helpful. A method for a ‘minimum program’ is helpful. The problems underlying such issues as natural language understanding will be significantly reduced. The problems underlying such issues as natural language understanding will be significantly reduced. There will be the possibility of having a truly creative machine. There will be the possibility of having a truly creative machine.

10. 30th March 2004GC7 Non-Classical Computing10 Computing with Irrational Sets 2 Minimum Program Computer States (bits) Problem Domain Names & Organisation Social sensitive feedback Contexts allows the use of rational sets The problem domain contains irrational sets. So we cannot use denotational semantics The problem domain contains irrational sets. So we cannot use denotational semantics

11. 30th March 2004GC7 Non-Classical Computing11 Social Consequences Since rules cannot be devised that are unambiguous Since rules cannot be devised that are unambiguous then there will always be a need for human judgement. then there will always be a need for human judgement. There will always be a wide range of perceptions of a problem domain There will always be a wide range of perceptions of a problem domain that cannot be predicted that cannot be predicted and hence planned for. and hence planned for.

12. 30th March 2004GC7 Non-Classical Computing12 Two Semantics of Irrational Sets Wittgenstein: Wittgenstein: Use family resemblance instead of sets. Use family resemblance instead of sets. Use word usage (and structures) instead of reference. Use word usage (and structures) instead of reference. Lakoff (and Johnson): Lakoff (and Johnson) 1 : Use prototypes (paradigms) Use prototypes (paradigms) Use metaphor instead of reference Use metaphor instead of reference [1] Lakoff and Johnson (1980) – Metaphors we live by Lakoff (1986) – Women, Fire and Dangerous Things The Challenge is how do you do this?