Artificial intelligence

The term artificial intelligence (AI) refers to the ability of a digital?computer?or computer-controlled?robot?to perform tasks commonly associated with intelligent beings. Since the mid-20th century, scientists have attempted to develop a system capable of carrying out tasks perceived as requiring human intelligence. Among the tasks that have been studied from this point of view are game playing, natural-language understanding, fault diagnosis, robotics, and supplying expert advice. Although computers can be programmed to perform these and other very complex tasks—and while advances continue to be made in computer processing speed and memory capacity—there are as yet no programs that can match human flexibility over wider domains or in tasks requiring much everyday knowledge.The earliest substantial work in the field of AI was done by British mathematician and computer pioneer Alan Turing. In 1950 Turing declared that one day there would be a machine that could duplicate human intelligence in every way and prove it by passing a specialized test. In this test, a computer and a human hidden from view would be asked random identical questions. If the computer were successful, the questioner would be unable to distinguish the machine from the person by the answers.

By the early 21st century no AI program had come close to passing the Turing test. Some programs had, however, attained the performance levels of human experts in performing certain specific tasks. AI in this limited sense could be found in applications as diverse as medical diagnosis, language translation, computer design, and voice or handwriting recognition.

Because the final goal of AI is to create computers that can “think” as humans do, some AI proponents have suggested that computers should be patterned after the human brain, which essentially consists of a network of nerve cells, called neurons . The first artificial neural network was developed in 1954, when the goal of “strong AI”—that is, a system that approaches human intelligence—was shared by many. In the early 2000s, artificial neural networks were capable of an array of sophisticated tasks, including recognizing faces and other objects from visual data, but the optimism over achieving strong AI had given way to an appreciation of the extreme difficulties involved.