The Physical Symbol System Hypothesis Flashcards
When is a physical system a computer?
It is a computer when it implements a Turing Machine, which is defined by:
- A finite alphabet of tape symbols
- A finite set of states
- A table of transition rules from one (symbol, state) pairing to another.
A physical system must also possess physically distinguishable features that correspond to the symbols, states and rules of that TM.
What is a universal Turing machine?
A universal Turing machine can solve all computable problems. All programmable computers are universal Turing Machines. A universal Turing machine can simulate all other kinds of Turing machines.
Explain why some computational problems are interesting, while others are not.
“interesting” problems reflect normative principles, like the rules of mathematics, the principles of good chess playing, language rules and so on. It means that these problems can be interpreted, as they represent something that is meaningful to us.
Give a proof of why AI is possible.
P1: We can design a TM to solve any computable problem.
P2: All interesting problems are computable
C1: We can design a TM to solve any interesting problem
P3: Being intelligent is being able to solve interesting problems
C2: We can design a TM that is intelligent.
P4: A digital computer can implement any TM
C3: We can build a digital computer that is intelligent.
-> Artificial intelligence is possible.
Define the physical symbol system hypothesis. Provide the explanations of the concepts used in this definition.
The hypothesis states: A physical system has the necessary and sufficient means for general intelligent action.
With necessary it is meant that all beings that show general intelligent action are physical symbol systems.
With sufficient it is meant that all physical symbol systems of a certain size can be ordered in such a way that they can show general intelligent action.
With general intelligent action it is meant in the way humans show intelligent action.
How does cognitive science borrow the concept of the PSSH?
Cognitive scientist are often asking the same questions about human intelligence as Symbolic AI researchers:
- Which rules or cognitive processes are deployed
- Where are those rules implemented
- Which symbols or representations are used for certain task
We often transform experiences of a physical world into symbol strings, process those strings and translate them back into physical movements.
Explain the Frame problem
It is hard to distinguish the relevant problems from the irrelevant problems in any given real-world context.
- How detailed do representations need to be?
- How deep must the search be to find a solution?
