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Category Generation. Alan Jern Charles Kemp Carnegie Mellon University. Category generation: Introduction. Observation: people can imagine and create new objects. Cobb salad. Spork. Griffin. T. Ward (1994). Category generation. Outline. Define category generation Modeling approach
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Category Generation Alan Jern Charles Kemp Carnegie Mellon University
Category generation: Introduction • Observation: people can imagine and create new objects Cobb salad Spork Griffin T. Ward (1994) Category generation
Outline • Define category generation • Modeling approach • Experiment
Category generation • Can occur at any level in a taxonomy Category level Exemplar level
Category generation This talk
Training Caesar Greek Classification x1 x2 x3 x4 x5 x6
Test Caesar Greek ? Classification x1 x2 x3 x4 x5 x6 xnew
Caesar Greek ? Classification x1 x2 x3 x4 x5 x6 xnew Training Caesar Greek Category generation x1 x2 x3 x4 x5 x6
Caesar Greek ? Classification x1 x2 x3 x4 x5 x6 xnew Test Caesar Greek xnew Category generation ? x1 x2 x3 x4 x5 x6
Past modeling approaches • Classification • Prototype model (Reed, 1972) • GCM (Nosofsky, 1985) • Rational model (Anderson, 1991) • ALCOVE (Kruschke, 1992) • SUSTAIN (Love et al., 2004) • Category generation • ?
Test Caesar Greek ? Classification x1 x2 x3 x4 x5 x6 xnew Caesar Greek xnew Category generation ? x1 x2 x3 x4 x5 x6
Our approach • Bayesian • Learn category distribution • Sample from that distribution
A category generation task … M M W G R G K B K X X R
An exemplar generation task Pieces Structure G K N B V S MX HF WR MX G K Slot 1 Slot 1 Slot 2 W M M Slot 2 N G G K B K X X R cf. Fiser & Aslin, 2001
Task model Structure ? G K N B V S MX HF WR MX G K Slot 1 Slot 2 ? Slots Slot 1 M W W M Slot 2 G N N G B K B K R X X R
Experimental Design • 18 CMU undergraduates • 3 structures (3 conditions)
Materials Slot 1 Z N Q J V S W K DB Seen combination RL Slot 2 XM HF
Results No item generated more than twice Humans Model 58% of responses (Hypothesis space: 1820 possible responses)
Results • Classification task • Rate likelihood of new instances Valid All Distractors 1 Seen Pairing 3 Seen Pairings 2 Seen Pairings
Conclusions • People can: • Learn latent category structure • Generate new category members • People are sensitive to frequency differences • Predicted by our probabilistic approach
Conclusions • Category generation is an understudied aspect of human categorization
Thanks • Faye Han • John Anderson • David Rakison Credit: RaynorGanan (ragbag.tumblr.com)