Podcast
Questions and Answers
What was the main reason for rejecting symbolic approaches to building agents?
What was the main reason for rejecting symbolic approaches to building agents?
- They were not suitable for time-constrained environments. (correct)
- They were too expensive to develop.
- They were not compatible with other AI systems.
- They were too complex to implement.
What is the common theme among alternative approaches to agency?
What is the common theme among alternative approaches to agency?
- The use of symbolic representations.
- The integration of human and artificial intelligence.
- The development of more complex AI systems.
- The rejection of symbolic representations. (correct)
Why is intelligent behaviour seen as linked to the environment an agent occupies?
Why is intelligent behaviour seen as linked to the environment an agent occupies?
- Because the environment is a source of energy for the agent.
- Because the environment is a necessary component of intelligent behaviour.
- Because the environment influences the agent's decision-making process. (correct)
- Because the environment provides additional information.
What is the term used to describe AI systems that emerge from the interaction of various simpler behaviours?
What is the term used to describe AI systems that emerge from the interaction of various simpler behaviours?
What is the main characteristic of situated approaches to agency?
What is the main characteristic of situated approaches to agency?
Why are alternative approaches to agency often referred to as 'reactive'?
Why are alternative approaches to agency often referred to as 'reactive'?
What is the main difference between symbolic and alternative approaches to agency?
What is the main difference between symbolic and alternative approaches to agency?
What is the common goal of alternative approaches to agency?
What is the common goal of alternative approaches to agency?
The subsumption architecture is arguably the best-known ______ agent architecture.
The subsumption architecture is arguably the best-known ______ agent architecture.
Rodney Brooks is one of the most vocal and influential critics of the ______ approach to agency.
Rodney Brooks is one of the most vocal and influential critics of the ______ approach to agency.
According to Brooks, intelligent behaviour can be generated without explicit ______ of the kind that symbolic AI proposes.
According to Brooks, intelligent behaviour can be generated without explicit ______ of the kind that symbolic AI proposes.
Brooks identifies two key ideas that have informed his research, including ______ and embodiment.
Brooks identifies two key ideas that have informed his research, including ______ and embodiment.
The subsumption architecture realizes an agent's decision-making through a set of ______ behaviours.
The subsumption architecture realizes an agent's decision-making through a set of ______ behaviours.
In Brooks's implementation, the behaviour modules are ______ state machines.
In Brooks's implementation, the behaviour modules are ______ state machines.
The task-accomplishing modules are assumed to include no complex ______ representations.
The task-accomplishing modules are assumed to include no complex ______ representations.
Intelligence is 'in the eye of the ______' - it is not an innate, isolated property.
Intelligence is 'in the eye of the ______' - it is not an innate, isolated property.
In many implementations, these behaviours are implemented as rules of the form situation- ______,
In many implementations, these behaviours are implemented as rules of the form situation- ______,
Brooks proposed arranging the modules into a ______ hierarchy, with the behaviours arranged into layers.
Brooks proposed arranging the modules into a ______ hierarchy, with the behaviours arranged into layers.
Lower layers in the herarchy are able to ______ higher layers.
Lower layers in the herarchy are able to ______ higher layers.
The idea is that higher layers represent more abstract ______.
The idea is that higher layers represent more abstract ______.
A behaviour is a pair (c,a), where c G P is a set of ______ called the condition, and a E A is an action.
A behaviour is a pair (c,a), where c G P is a set of ______ called the condition, and a E A is an action.
A behaviour (c,a) will fire when the environment is in state s E S if and only if see(s) E ______.
A behaviour (c,a) will fire when the environment is in state s E S if and only if see(s) E ______.
Let Beh = ((c,a) I c E P and a E A) be the set of all such ______.
Let Beh = ((c,a) I c E P and a E A) be the set of all such ______.
Study Notes
Limitations of Symbolic/Logical Approaches
- Researchers questioned and rejected the assumptions of symbolic/logical approaches to building agents due to their limitations in operating in time-constrained environments.
- Minor changes to the symbolic approach, such as weakening the logical representation language, were deemed insufficient to overcome these limitations.
Alternative Approaches to Agency
- In the mid-to-late 1980s, researchers began exploring alternatives to the symbolic AI paradigm.
- Common themes among these approaches include:
- Rejection of symbolic representations and decision-making based on syntactic manipulation of representations.
- Intelligent, rational behavior is seen as inherently linked to the environment an agent occupies.
- Intelligent behavior emerges from the interaction of various simpler behaviors.
Characterization of Alternative Approaches
- Alternative approaches to agency are sometimes referred to as:
- Behavioral (developing and combining individual behaviors).
- Situated (agents situated in an environment, rather than being disembodied from it).
- Reactive (systems reacting to an environment without reasoning about it).
Subsumption Architecture
- Developed by Rodney Brooks, a prominent critic of the symbolic approach to agency
- Brooks' three key theses:
- Intelligent behavior can be generated without explicit representations of the kind that symbolic AI proposes
- Intelligent behavior can be generated without explicit abstract reasoning of the kind that symbolic AI proposes
- Intelligence is an emergent property of certain complex systems
- Brooks' two key ideas:
- Situatedness and embodiment: 'Real' intelligence is situated in the world, not in disembodied systems
- Intelligence and emergence: 'Intelligent' behavior arises as a result of an agent's interaction with its environment
Defining Characteristics of Subsumption Architecture
- An agent's decision-making is realized through a set of task-accomplishing behaviors
- Each behavior is an individual action function that continually takes perceptual input and maps it to an action to perform
- Behavior modules are assumed to include no complex symbolic representations and do no symbolic reasoning
- Behaviors are often implemented as rules of the form situation-action, which simply map perceptual input directly to actions
Subsumption Hierarchy
- Many behaviors can 'fire' simultaneously, requiring a mechanism to choose between the different actions selected
- Behaviors are arranged into a subsumption hierarchy, with lower layers able to inhibit higher layers
- Higher layers represent more abstract behaviors, with lower layers having higher priority
Formal Model of Subsumption Architecture
- The see function represents the agent's perceptual ability and remains unchanged
- Decision function action is realized through a set of behaviors, together with an inhibition relation holding between these behaviors
- A behavior is a pair (c,a), where c is a set of percepts called the condition, and a is an action
- A behavior (c,a) will fire when the environment is in state s if and only if see(s) belongs to c
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Description
This quiz explores the limitations of symbolic and logical approaches to building agents, and the need for a new approach to operate in time-constrained environments.
