Concepts as Action-Oriented as 'Search' Muhammad Aurangzeb Ahmad Department of Computer Science and Engineering University of Minnesota [email_address] http://www.tc.umn.edu/~ahma0089/

Muhammad Aurangzeb Ahmad Department of Computer Science and Engineering University of Minnesota

[email_address] http://www.tc.umn.edu/~ahma0089/

Outline Background Information Clark-Prinz Contra Fodor Concepts, Actions and Search Engines Networks and Search Engines Concepts: Networks of Networks Putting it all together Criticism Conclusion

Background Information

Clark-Prinz Contra Fodor

Concepts, Actions and Search Engines

Networks and Search Engines

Concepts: Networks of Networks

Putting it all together

Criticism

Conclusion

Background Major Issues (SEP) Ontology of Concepts Structure of Concepts Empiricism and Nativism about Concepts Relation between Concepts and Natural Language Concepts and Conceptual Analysis Major Theories / Paradigms about Concepts Classical Theory: Concepts have a definitional structure Conceptual Atomism No semantic structure

Major Issues (SEP)

Ontology of Concepts

Structure of Concepts

Empiricism and Nativism about Concepts

Relation between Concepts and Natural Language

Concepts and Conceptual Analysis

Major Theories / Paradigms about Concepts

Classical Theory:

Concepts have a definitional structure

Conceptual Atomism

No semantic structure

Major Theories about Structure Prototype Theory Concepts have a probabilistic structure and have to satisfy a sufficient number of conditions. Theory Theory Concepts are like scientific theories and are defined in terms of one another. Exemplar Theory Concepts are represented as examples of categories Proxytype Theory Concepts are copies of perceptual representations in long term memory and can be activated in working memory

Prototype Theory

Concepts have a probabilistic structure and have to satisfy a sufficient number of conditions.

Theory Theory

Concepts are like scientific theories and are defined in terms of one another.

Exemplar Theory

Concepts are represented as examples of categories

Proxytype Theory

Concepts are copies of perceptual representations in long term memory and can be activated in working memory

Clark-Prinz Contra Fodor Fodor To possess a concepts is "about being able to think about the things or states of affairs in question." Clark & Prinz Concepts are (mostly) for acting. “ We have representations in order to act, and the way we act, on the basis of our representations, may have some impact on what they mean.” (Prinz, Clark 2004)

Fodor

To possess a concepts is "about being able to think about the things or states of affairs in question."

Clark & Prinz

Concepts are (mostly) for acting.

“ We have representations in order to act, and the way we act, on the basis of our representations, may have some impact on what they mean.” (Prinz, Clark 2004)

The Frame Problem Given a massive reservoir of data how does one find “the right stuff (information, data) to consider (update, or use in reasoning) at the right time.” (Andy Clark 2002) Given that one's knowledge base is potentially immense how does one determine which features of the world to attend to. Even the features of relevance will bring up another problem.

Given a massive reservoir of data how does one find “the right stuff (information, data) to consider (update, or use in reasoning) at the right time.” (Andy Clark 2002)

Given that one's knowledge base is potentially immense how does one determine which features of the world to attend to.

Even the features of relevance will bring up another problem.

Search Engines The Problem Faced by Search Engines Massive repository of data and a query. The set of documents that are superficially relevant to the query are literally in tens of millions. Solution: Syntactical approaches work for small databases but not for global search in large databases. Divide the large database into smaller units but this assumes that one already knows what the boundaries of the sub-domains are.

The Problem Faced by Search Engines

Massive repository of data and a query. The set of documents that are superficially relevant to the query are literally in tens of millions.

Solution:

Syntactical approaches work for small databases but not for global search in large databases.

Divide the large database into smaller units but this assumes that one already knows what the boundaries of the sub-domains are.

Search Engines: Google et al. Information about information is still information. Instead of looking at the content look at the links between the pages. Search based on links instead of purely on the content is immensely more powerful Example: Do a dumb syntactical search – k pages Expand the links and get the linked pages Compute the rank of the pages The ones with the higher rank are more relevant

Information about information is still information.

Instead of looking at the content look at the links between the pages.

Search based on links instead of purely on the content is immensely more powerful

Example:

Do a dumb syntactical search – k pages

Expand the links and get the linked pages

Compute the rank of the pages

The ones with the higher rank are more relevant

Example: Simplified PageRank Assume a Uniform Distribution of Pages Pages: a, b, c, d Assume uniform distribution initially PR(a) = PR(b) + PR(c) + PR(d) After reassignment PR(a) = PR(b)/2 + PR(c)/1 + PR(d)/3 Generalization PR(u) = Σ PR(v)/N, v in B b c d a b c d a

Assume a Uniform Distribution of Pages

Pages: a, b, c, d

Assume uniform distribution initially

PR(a) = PR(b) + PR(c) + PR(d)

After reassignment

PR(a) = PR(b)/2 + PR(c)/1 + PR(d)/3

Generalization

PR(u) = Σ PR(v)/N, v in B

Clark's Approach The Human Cognitive System is doing something similar when its solving the frame problem. Use Second Order Information Objections Isn't this circular? Encoding Distributed vs. Central Verification

The Human Cognitive System is doing something similar when its solving the frame problem.

Use Second Order Information

Objections

Isn't this circular?

Encoding

Distributed vs. Central

Verification

Beyond AC: More on Concepts and Search In the case of the webpages there is content but we choose to (mostly) ignore it. What does content constitute when one is discussing human cognition? Why stop at second order information? When you have a set of returned features you look at not just the returned features and their rankings but the 'links' between the features The result you get can be thought of as one mechanism about how agents like us would possess concepts

In the case of the webpages there is content but we choose to (mostly) ignore it.

What does content constitute when one is discussing human cognition?

Why stop at second order information?

When you have a set of returned features you look at not just the returned features and their rankings but the 'links' between the features

The result you get can be thought of as one mechanism about how agents like us would possess concepts

Concepts and Search Before After

Before

After

Similarities with other theories Theory-Theory: Concepts are defined by their role in a larger 'theory' of things. Prototype Theory: Concepts have a probabilistic structure and have to satisfy a sufficient number of conditions. Instead of Conditions now you have graph similarity. Exemplar Theory: Exemplars are just the representations (graphs) which are most likely to be returned by the query about the category.

Theory-Theory:

Concepts are defined by their role in a larger 'theory' of things.

Prototype Theory:

Concepts have a probabilistic structure and have to satisfy a sufficient number of conditions.

Instead of Conditions now you have graph similarity.

Exemplar Theory:

Exemplars are just the representations (graphs) which are most likely to be returned by the query about the category.

Issues: Representation & Prop. Attitudes Why are certain objects considered to be more representative of a category as compared to others? How can we have certain propositional attitudes without having relevant mental representations? Example: Drunk pink elephants don't fly in space shuttles.

Why are certain objects considered to be more representative of a category as compared to others?

How can we have certain propositional attitudes without having relevant mental representations?

Example: Drunk pink elephants don't fly in space shuttles.

Miscellaneous Issues Problem of Communication If the concepts that people have do not always correspond with one another then: How can people possible communicate with one another? Does it even make sense to say that they have the same concept? Concept Pragmatism What matters that people are able to act? Sufficient similarity between their respective 'concepts How to deal with Concept Hierarchies? Subcategories are not necessarily subgraphs Think of these as collapsing Nodes

Problem of Communication

If the concepts that people have do not always correspond with one another then:

How can people possible communicate with one another?

Does it even make sense to say that they have the same concept?

Concept Pragmatism

What matters that people are able to act?

Sufficient similarity between their respective 'concepts

How to deal with Concept Hierarchies?

Subcategories are not necessarily subgraphs

Think of these as collapsing Nodes

Issues: Problem of Composability Some concepts are not simply sum of their parts. Example: People associate certain traits with fish and other traits with pets. However pet fish conjures up an different image such that: Pet Fish ≠ Pet + Fish When dealing with concepts which appear to be composed of other concepts people use other background knowledge to make sense of the concept.

Some concepts are not simply sum of their parts.

Example: People associate certain traits with fish and other traits with pets. However pet fish conjures up an different image such that:

Pet Fish ≠ Pet + Fish

When dealing with concepts which appear to be composed of other concepts people use other background knowledge to make sense of the concept.

Issues: Problem of Composability (ii) Pet Fish Common Traits Pet Fish

Pet Fish

Common Traits

Pet Fish

Criticism How do we deal with cases that involve: Abstract Knowledge - Numbers Logical Operatives

How do we deal with cases that involve:

Abstract Knowledge - Numbers

Logical Operatives

Conclusion A complementary theory of concepts Concept Empiricism Structural Pluralism Concept deployment is an online process

A complementary theory of concepts

Concept Empiricism

Structural Pluralism

Concept deployment is an online process

Thank You ! Questions