Prototype theory
<p>Jun 28, 2011 05:14 PM
 
prototype theory is  graded categorization in cognitive science
where some members of a category are more central than others.
 
eg  give an example of FURNITURE:  people will say CHAIR more oftern than STOOL.
 
prototype theory 
contrasts with <b>DEFINITION or (rule) based models</b> eg
a BIRD =  animals with FEATHERS + BEAK + ability to fly
 
in prototype theory:  a  ROBIN would be more prototypical than a PENGUIN.
this leads to a graded notion of categories... which is a central notion in many models of cognitive semantics
eg as in George Lakoff.   article emphasizes work by Eleanor Rosch.
 
Eleanor Rosch: FURNITURE example:
chair is most frequently picked, then sofa, then couch, then table, then dress
 
at the bottom is telephone and refrigetaor and stove and sewing machine, waste basket.
 
Prototypical members have
faster response times ...
exemplars are more frequent... more readily accessible
 
Basic Level Categories:  
 
when asked  What are you sitting on?  most ppl prefer to say CHAIR rather than
a subordinate  kitchen chair or a superordinate  furniture.
 
Basic categories:  sensory-motor affordances:  chair... bending one's knees
fruit:  picking it up and putting it in your mouth
 
subordinate level:  dentist's chair or kitchen chair... not new info is added that is significant
at the superordinate level...  hard to conceptualize  (eg hard to draw a picture of furniture)
 
Rosch 1978... basic level.... highest cue validity...
eg animal has no visual representation  ... but
DOG does, BIRD does, FISH  ... full of info content... easy to recognize.
 
but  basic level categories are a decomposition info maximally informative categories.
 
Read the Wittgenstein paragraph on GAMES  (board games, card games, playing catch, tennis, chess)
 
the notion of family resemblance is called for a notion of conceptual distance.
 
Peter Gardenfors... Conceptual Spaces...  categories are multi-dimensional feature spaces that are convex.
 
Tall man vs tall skyscraper  or small mouse vs small elephant... quite different...
must be contextualized.
 
 
 
 
 
 
 
 
 
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