The Four Types of Artificial Intelligence
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Rules Can Learn Has Memories Knows Other Minds Exist Aware of Emotion True AI Reactive Machines Limited Memory limited Theory of Mind Self Aware
The Four Types of Artificial Intelligence
What to know about the different levels of AI
By Sam Costello Sam Costello Writer Ithaca College Sam Costello has been writing about tech since 2000. His writing has appeared in publications such as CNN.com, PC World, InfoWord, and many others. lifewire's editorial guidelines Updated on March 21, 2021 Reviewed by Michael Barton Heine Jr Reviewed by Michael Barton Heine Jr Michael Heine is a CompTIA-certified writer, editor, and Network Engineer with 25+ years' experience working in the television, defense, ISP, telecommunications, and education industries. lifewire's editorial guidelines Tweet Share Email Tweet Share Email Smart Home Your Best Year Ever: College Tech Tips Amazon Appliances & Lighting Google Artificial Intelligence, or AI, is increasingly becoming a part of our everyday lives, even if we don't always know it. Because it's already here and only going to become more critical in the future, it's essential to understand the four types of artificial intelligence, how they're distinct, and which ones are in use today.Overview of Artificial Intelligence
Artificial Intelligence is measured in comparison to the functions of the human mind. A true, fully complete AI could replicate—and likely extend—a human brain's functions. It would be self-aware, have consciousness and memories, could learn and make predictions about likely future events—and would do these things on its own, without human intervention or input from programmers.The Four Types of AI Reactive Machines
The first and most basic kind of AI is Reactive Machines. These machines have intelligence that exists almost entirely in the present moment (eat your hearts out, meditators!). Programmers build Reactive Machines around complex sets of rules. In addition to those rules, they may include neural networks that allow them to learn and adapt in the moment. Crucially, though, this type of AI can't form memories or act based on past experiences. Because they can't create memories, they can't take past occurrences, even those that happened to them, and use them to make new decisions. In this way, they're restricted to the scenarios and information covered in their sets of rules. Because of this limitation, one can trick Reactive Machines into being defeated by forcing them to operate outside their limited set of rules. Reactive Machines also don't have a concept of the future. They can use their rules to make extrapolations about what might come next, but only within the boundaries established by their rule sets. Because they can't change their future actions based on past occurrences, Reactive Machines can't learn. Examples: IBM Deep Blue (plays chess), IBM Watson (won at Jeopardy), Google AlphaGo (plays Go), recommendation engines like those found in streaming video and audio services Learn more about Reactive Machines AIThe Four Types of AI Limited Memory
This more-advanced AI type has the abilities of reactive machines but adds a concept of the past. While Limited Memory AIs aren't forming memories, they are aware of a recent past and can use the data captured at that time to influence their decisions. Self-driving cars are the best example here. They continuously monitor the conditions around them—what other vehicles are doing, where objects are, how pedestrians are moving, etc.—and holding that information in a temporary state to influence their actions. As you might imagine, Limited Memory AIs process tremendous amounts of data and make decisions very quickly. This AI level is called "Limited Memory" because these past experiences aren't stored permanently, and it can't use them for all future learning. Instead, these past experiences are saved for a short time while they're practical and then discarded. Examples: Self-driving cars Get an in-depth view of Limited Memory AIThe Four Types of AI Theory of Mind
With Theory of Mind AI, we get closer to the science-fiction ideal of artificial intelligence. This level of AI includes all of the aspects of Reactive Machines and Limited Memory. But it adds a crucial and complex bit of understanding: that living objects (people, animals, etc.) around them have a thing called a "mind." Once an AI understands that other creatures have minds, it can then understand that it should learn and adjust its decisions based on those minds. It then understands minds generate thoughts and emotions (even if it doesn't truly understand what those things are yet) and that thoughts and emotions will influence behavior. The AI has to use those factors in its decision-making framework. Examples: There are no known examples of Theory of Mind AI in existence (though some robots that attempt to understand and simulate point a direction for this type) Learn more about Theory of Mind AIThe Four Types of AI Self Aware
Self-Aware AI is the final and most complex, and mature level of AI. It's a genuinely self-aware intelligence. Any AI from science fiction falls into this category. It's an entity with true consciousness. It's aware of its existence and its internal states (and potentially emotions), can form memories of the past, and make predictions. It's aware of other consciousnesses and can take them into account when making decisions. Crucially, it can learn and become more intelligent based on its experiences. A Self-Aware AI would require extremely flexible programming logic, an ability to update its logic on its own, and a tolerance for inconsistency since human behavior isn't always neatly predictable or rigidly patterned. Examples: Self Aware AI doesn't exist currently and is likely many years away from being achieved Learn more about Self Aware AIThe Four Types of AI Compared
The four key types of AI, and their key characteristics, are listed below for easy reference and comparison. AI Type FollowsRules Can Learn Has Memories Knows Other Minds Exist Aware of Emotion True AI Reactive Machines Limited Memory limited Theory of Mind Self Aware