Chapter 8 Flashcards
you need ______ to have knowledge and you need knowledge to function
concepts
What is the definition possibility of understanding concepts
You have a dictionary like description of concepts.
- PROBLEM: even simple terms resist being defined and exceptions are common
Wittgenstein proposed “family resemblance” to explain categories. Explain.
There are no defining features that every member has
- but there are features that are common among most depending on the subgroup (characteristic features)
- it is a matter of degree (the more characteristics the more likely it is a member)
What is prototype theory?
- the centre of a category = prototype
- It is the average of all the members of the category you’ve seen
- all judgements about members are made in reference to this ideal
- different people have different prototypes
- captures the family resemblance idea
Graded membership?
- category membership is a more or less decision
- objects closer to the centre prototype are “better” members than those far away
What were the correlations between the sentence verification task, the production task and the rating task when investigating prototype theory.
- Rxn times were faster for sentences with prototypical members
- The members with fastest rxn time were also the first to be mentioned in the production task (naming birds)
- The same members were rated as more prototypical (birdier)
= conclusion: people perform these tasks by comparing to their prototype
What happened when Rosch made participants generate sentences about a category?
if subject said “I saw 2 birds in a tree”
- experimenter replaces category name with either protoypical or non-prototypical member
- New sentences are then shown to new subjects and asked to rate silliness
- The non prototypical members generated the most silly sentences
CONCLUSION: participants are forming these sentences with the prototype in mind ( ie. certain members are privileged)
What is basic-level categorization?
A level of categorization hypothesized as the “natural” and most informative level, neither too specific nor too general.
- these categories are privledged (used most often)
- Usually represented by one word (ie.chair)
What is exemplar theory
- similar to prototype theory in that it involves comparison to a standard
- however the standard is an example of that category that you have seen in the past (differs b/w people)
How would the exemplar theory explain the evidence that supports prototype theory (typicality effects)
- verification of category being faster for typical members is because those examples are common and well primed in your memory
- The same logic can explain the production task: you name the members that are most common in your memory
So which theory is correct, prototype or exemplar? explain why.
BOTH - each has an advantage
- THere are instances in which the quick summary of prototypes is most useful
- However exemplars provide the specific info that is lost
Can the preferred type of knowledge can change for a person? can they be combine
- yes you may have extensive knowledge for horses (exemplar) and general knowledge about cars (prototype)
- your knowledge within a subject cna change: when you’re learning you think of specific examples (exemplar) then you switch to prototype and when you become an expert once again you can think of specifics
- You also have the option to combine both
WHat experiment demonstrated that typicality and category membership can be independent of eachother. (even-ness)
Armstrong and gleitman asked participants to rate even numbers according to their even-ness. Despite all clearly belonging to the category “even” subjects were just as consistent at rating typicality as they were for more typical categories like ‘dog’
Why did children agree that a toaster could become a coffee pot, but a skunk couldn’t become a racoon?
Because in the animal’s case is is not merely a function of having the relevant features - it has to do with the broader understanding of that category (genetics/inheritance)
- It is these “deep features” that matter in this case
- They reason differently for artifacts vs. natural kinds (animates)
- same is true with counterfeit bills, and squished lemons
what do prototype and exemplar theory both have in common at their base
judgements of resemblance (either to a prototype or a remembered instance)
Judgements of resemblance is based on what shared features actually matter. How do we decide which are important and which to discard?
It depends on your general belief about the concept and it varies from category to category
What are categorization heuristics?
strategies for categorization that give up accuracy for efficiency
- Using typicality (resemblance to prototype/exemplar) will lead to correct categorization most of the time
- The categorization heuristic emphasizes superficial characteristics.
ex. resemblance
What are explanatory theories? How do they influence your understanding of concepts?
= Implicit “theories” formed on beliefs and knowledge about a category and other related concepts - more holistic approach that affects:
- Membership judgements
- Possible new members
- How fast we learn new concepts (theory gives a category coherence which makes it easier to learn)
- serve the same function as a scientists theory though les precise
- can be inaccurate
If participants are willing to infer that a new fact about a robin is also true of ducks but not vice versa what are they being guided by?
Typicality - subjects are more willing to extrapolate facts about typical members to the whole category than the other way around
If participants are willing to infer that a new fact about enzymes in a gazelle is also true of a lion but not vice versa what are they being guided by?
broader beliefs/knowledge about cause and effect
- in this case knowledge about the food chain: A lion eats a gazelle and is then likely to take on some of it’s properties but not the other way around
What is the difference between artifacts and natural kinds
Natural kinds: sharp boundaries and characteristics that are unchanging/predictable as they are essential in order to survive. (judged based on biology/chemical composition))
Artifacts: Man made objects. Fuzzy boundaries, characteristics can change and membership can be temporary
> people reason differently for each based on their cause and effect beliefs
What neurological evidence supports the argument that separate brain systems are responsible for different types of categorical knowledge
- fMRI scans show that different brain areas are active when thinking about animate vs. inanimate things
- Brain damaged people can lose the ability to name only certain categories of things. Can be broad (can’t name nonliving things) or specific (can’t name fruits)
