AI- 19

Engineering Aim

- To engineer, or provide computational principles and engineering techniques for, "useful" artefacts that are arguably intelligent. ○ Mechanistic similarity to human or animal minds/brains is not necessary. - The artefact may be useful in one of a variety of domains: ○ Industry ○ Mathematics ○ Art ○Everyday life

What is Intelligence?

- When we say that humans are intelligent, we mean they exhibit certain high-level cognitive abilities, including: ○ Carrying out complex reasoning >> E.g., solving physics problems, proving mathematical theorems ○ Drawing plausible inferences >> E.g., diagnosing automobile faults, solving murder cases ○ Using natural language − E.g., reading stories, carrying out extended conversations ○ Solving novel, complex problems >> E.g., completing puzzles, generating plans, designing artefacts - Does not include: ○Executing motor skills or autonomic activity (breathing, reflexes etc.)

MYCIN

- is an example of an early expert system. - Designed to diagnose bacterial infections. - List of possible bacterial culprits provided, ranked from high to low based on the probability of each diagnosis. - Antibiotic treatment regimen, dose adjusted for patient's body weight, was also given

Examples Of Weak AI - Agents

○ Autonomous entity that works in a defined environment. ○ Agent achieves goals within environment using: >> Percepts - observations of the environment obtained through sensors >> Actions - made on the environment using actuators

Representing Problems As Symbols

- AI programs reduce problems to symbols. - Problems are solved through the manipulation of these symbols. - The manipulation of these symbols can seem intelligent. - The computer does not "know' what the symbols mean. Example - Scenario: ○ A farmer needs to cross a river by boat taking with him his dog, goose, and a sack of corn. - Constraints: ○ The boat is small and can only hold one item along with the farmer. ○ The dog can't be left alone with the goose. The dog will eat the goose. ○ The goose can't be left alone with the corn. The goose will eat the corn. - Problem: ○ What is the order in which the farmer transfers his property across the river? Symbolic Representation - Dog = d - Goose = g - Corn = c - At the start of the problem, all three are on the left bank of the river. The right bank is empty. ○ Start state: L(d,g,c), R() - The goal is to get all three across to the right bank: ○ Goal state: L(), R(d,g,c) - Operators are used to indicate actions the farmer can take: ○ Row dog to right bank = →(d) Row corn to left bank = ←(c)

What is Artificial Intelligence? and its aims

- Artificial intelligence is the computational study of structures and processes that support intelligent behaviour. - Term first coined in 1956: ○ Dartmouth Summer Research Project on Artificial Intelligence - Areas of research include: ○ Computer vision ○ Natural language processing ○ Robotics ○ Knowledge-based systems ○ Machine learning ○ Planning 3 Aims of Artificial Intelligence - Three interrelated aims: ○ Engineering aim ○ Psychological aim ○ General/Philosophical aim

Philosophical View Of Intelligence

- Behaviourist/ Functionalist approach: ○ External behaviour matters ○ If it behaves intelligently, then it is intelligent ○ Turing test - Cognitive approach: ○ What happens internally matters ○ We must consider how it thinks, not just look at the behaviour ○ Chinese room

Examples Of Weak AI - Agents

- Expert System ○ Computer system that emulates decision making ability of a human expert. ○ Two components: 1. Knowledge base - repository of information/facts about the world as well as rules that can be applied to the facts. Rules usually have an IF-THEN representation. 2. Inference engine - applies rules to known facts to deduce new knowledge.

Examples Of Weak AI

- IBM Deep Blue ○ Chess playing computer ○ Won a game against reigning world champion Garry Kasparov in 1996, losing the overall match. ○ Won the match against Kasparov in 1997; first computer to do so in a match under standard chess tournament time controls. ○ Deep Blue was programmed with history of Kasparov's previous games. ○ Programming was modified between games to avoid traps. ○ Kasparov was not permitted to study Deep Blue's previous games

Curiosity Rover

- Part of the Mars Exploration Program to study: ○ Whether Mars could have ever supported life. ○ Role of water on Mars ○ Climate and geology of Mars - Curiosity rover navigates surface of Mars autonomously.

The Turing Test

- Proposed by Alan Turing in his 1950 paper "Computing Machinery and Intelligence". ○ Defines criteria for determining machine intelligence ○ "Are there imaginable digital computers which would do well in the imitation game?" - Imitation game: ○ Three players - A, B, and C ○ A is a man and B is a woman. C, the interrogator is of either gender ○ Player C is unable to see either player A or player B ○ C asks A and B questions, trying to determine which of the two is a man and which is the woman - Standard Turing test: ○ Three players - A, B, and C ○ A is a computer and B is a person of either sex. C, the interrogator is also a person of either gender ○ Player C is unable to see either player A or player B ○C asks A and B questions, trying to determine which of the two is human and which is the machine

Strong AI versus Weak AI

- Strong AI ○ The view that a computer could become self-aware and exhibit intelligent behaviour. - Weak AI ○ The view that computers could not become self-aware and reason. ○ Can be used to solve specific problems in a well-defined domain

Dangers of AI

- Technological Singularity ○ What happens if we make a system that is as "intelligent" as ourselves? ○ What happens when it can modify itself? - This is "the" technological singularity. ○ The assumption is that it will quickly increase its own intelligence far beyond own. ○ It is called a singularity because looking to the past provides little, if any, guidance for the future. ○ Computers now control most of our fundamental industries, etc., what happens when they are smarter than we are? - Closer to home - dangers right now ○ Used to polarise nations & peoples ○Armed weapons platforms

The Chinese Room

- Thought experiment proposed by John Searle in his 1980 paper "Minds, Brains, and Programs". - Refutes functionalist viewpoint: ○ "The appropriately programmed computer with the right inputs and outputs would thereby have a mind in exactly the same sense human beings have minds" - Premise: ○ Person in a closed room who has no understanding of Chinese. ○ Room contains a manual with instructions detailing the appropriate response, in Chinese characters, to every possible input, also in Chinese characters. ○ Person can communicate via written responses with the outside world through a slot in the door. - Scenario: ○ A Chinese person passes messages written in Chinese, to the person in the Chinese Room. ○ Person in the room responds using the manual; they appear to be conversant in Chinese despite not understanding any of the communication. - Argument: ○ Without "understanding", a machine's activity cannot be described as "thinking". Since a machine does not think, it does not have a "mind" in the same way you would say a person does

Psychological Aim

- To create computational principles, theories or systems that provide a greater insight on cognition in human or animal minds/brains.

General/Philosophical Aim

- To create computational principles, theories or systems that provide a greater insight on cognition in general. ○ Human made artefacts ○ Naturally occurring organism ○ Cognizant entities yet to be discovered. - Includes looking at philosophical issues like the nature of intelligence, thought, consciousness