DD303 Concepts

DD303 Concepts

1. Intro

   • Concepts
     • "General ideas that apply to every member of a category"
     • Internal to mind; categories external
     • Can map to multiple categories
       • eg "chest'

2. Categorisation

   • Bruner
     • Individual things in terms of group membership
     • Implies
       • Conceptual grouping via behaviour
         • eg petting dogs
       • Different behaviour = thinking differently about different concepts
   • Sorting tasks
     • Ross & Murphy
       • Eggs
         • Breakfast
         • Dairy

3. Concepts & Cognition

   • Makes it easier to remember stuff
   • Semantic classification
     • Recognition
     • Units of semantic membership?
       • Store facts
       • R'ship between concepts
         • eg cat & heart
   • Enable inferences
     • Reasoning
     • Simplify remembering info
   • Lexical concepts
     • Category represents what we believe 'cat' to mean

4. Explaining Categorisation

   • 1) Classical view
     • Things belonging to category
       • Common properties
         • Necessary condition
       • If item has properties common to category's members, it must be a member too
         • Sufficient condition
     • Evidence for:
       • Bruner et al
         • People associate common properties with category members
     • Criticisms
       • Typicality
         • Robin more typical bird than penguin
         • "All or nothing" ≠ reality
           • Rosch
             • Ps verified sentences 'Robin is a bird' quicker than 'Penguin is a bird'
               • Robin = more typical
         • Categories have rich internal structure
           • Not explained by classical view
       • Borderline cases
         • If "all or nothing" ≠ borderline
         • Red/orange?
         • McCloskey & Glucksberg
           • Ps rated items inconsistently & @ different times
           • eg bookends as furniture
       • Intransitiivty
         • If A is in B and B is in C then A is in C
         • Hampton
           • Ps judgements not fit with rule
           • eg car seats
       • Lack of definitions
         • Wittgenstein
           • All members share common properties?
             • Games?
               • Olympic
               • Card
               • Board
           • Most categories indefinable
   • 2) Prototype view
     • Prototype
       • Most typical examplar of category
       • Object = member if meets enough properties of category - ie similarity to prototype
         • ie NO necessary condition
       • Property can have many values
         • eg apple colour
       • Typicality weightings
         • Highly typical instances match highly-weighted properties
         • Typicality correlated with how widely members share attributes
     • Criticisms
       • Meaning of typicality effects
         • Armstrong et al
           • Concepts not organised around prototype
             • BUT existence of typicality effects aren't conclusive evidence membership determined by similarity to prototype
               • Suggests: Dual process model (ie combine both theories)
                 • 1) Concept core - judge category membership
                 • 2) Identity procedures - match instances to category
       • Context sensitivity
         • Typicality effects alter w/ context
           • Medin & Shoben
             • Spoons
               • Metal more typical than wooden
               • Small more typical than large
               • BUT large wooden more typical than small wooden!
       • Complex concepts
         • not cope with concept combinations
           • eg red car
           • How combine prototypes?
             • eg Stone lion?
   • 3) Common-sense theories
     • Issues with similarity based approaches (classical & prototype)
       • Meaning
       • Items can share infinite things in common
         • Plumb and Lawnmower
     • Evidence for:
       • Rips
         • Pizza & US 1/4
         • 3rd object: more like pizza but more similar to 1/4
           • Dissociation between category & similarity
             • Underlying theory not just similarity based
       • Kiel
         • Developmental aspects
           • Hybrid zebra w/ horse insides
             • 4yrs = zebra (appearance); 7yrs = horse (lineage)
         • Characteristic defining shift w/ age
     • Criticisms
       • Just because deeper knowledge suggested (not just similarity) doesn't make it more correct
       • "theory" poorly defined; common sense not compatible w/ science theory
         • More like 'knowledge' - Murphy
       • No explanation for complex concepts
       • May just replace 'similarity' w/ 'theory'
         • Both woolly terms
   • 4) Psychological Essentialism
     • Assumes deeper principles
     • Objects categorised according to unobservable shared 'essential' properties
       • Superficial properties known, may not be able to define essential properties
       • Medin & Ortony
         • 'Placeholder' for essential properties - empty if cant define
     • Evidence for:
       • Innate potential
         • test kids belief re innate properties
         • Animal switch from its bio parents to new ones
           • Pre-school kids: Kangaroo & goat = pouch & hop (ie innate kangaroo property)
         • Children more nativist
         • Gellman & Wellman
           • Young kids: insides more import re id of category
     • Criticisms
       • Context & perspective
         • Malt
           • Categorisation depend on context & goals of perceiver
           • Water = puddles or tears
       • Expert opinion
         • Malt
           • Ps ask expert re borderline natural item than for artefact (eg soap)
           • Natural categories may involve psych essentialism as Ps recognise info experts bring
     • Gelman
       • Children
         • Look beyond the obvious in various ways
           • Learning words
           • Generalising knowledge to new category members
           • Reasoning about insides of things
           • Beliefs re nature vs nurture
           • Constructing causal explanations
       • Certain categories (eg lion; female) have underlying reality - cannot be directly observed
       • Psych essentialism = early cognitive bias?
       • Against view that children are concrete thinkers

5. Where next?

   • All theories flawed!
     • Classical
       • Necessary & sufficient conditions only id for few categories
     • Prototype
       • Not explain context sensitivity or complex concepts
     • Theory theory
       • Imprecise, no definitions, cant explain complex concepts
     • Psych essentialism
       • Mixed evidence, much doesn't map to 'essences'
   • All categorisation the same?
     • Each approach for different scenarios ie not a single approach
     • Determinate # of different kinds of category
       • Classical - for definitions
       • Prototype - rapid categorisation or fuzzy matching
       • Theory based - considered judgements, explanation for category membership
       • Psych Essentialism - integrate scientific knowledge, expert view
     • Smith & Sloman
       • Replicate Rips (pizza)
       • Same dissociation is Ps think out loud
       • 2 modes
         • Similarity based
         • Rule based
     • Language
       • Categories have labels
         • Words & concepts linked
         • Some words to label items in different categories
           • eg stone lion
       • Malt
         • "Shampoo bottle"
           • Not a bottle!
   • All concepts the same?
     • Well defined
       • amenable to definition
       • Classical view
       • Not explain typicality!
     • Fuzzy
       • Prototype
         • eg "red"
     • Common-sense
       • "sparrow"; "introvert"
         • Theory or Essentialism
   • All categorisers the same?
     • Different approaches depend on knowledge/skill?
       • Medin
         • Trees
         • Taxonomists, maintenance workers, landscapers
           • Different approach
     • Lynch et al
       • Typicality ratings vary between experts & novices