Chapter Nine - Knowledge Flashcards
Conceptual Knowledge
knowledge that enables us to recognize objects + events
-make inferences about their properties
Concept
-mental representation used for a variety of cognitive functions
Categorization
process by which things are placed into groups
What are categories?
all possible examples of a particular concept
Concepts provide ______ for categories
the rules
Why are categories useful?
- helpful to understand individual cases not previously encountered
- “Pointers to knowledge”
How are categories pointers to knowledge?
- categories provide a wealth of general information about an item
- allow us to identify the special characteristics of a particular item
How do we determine category membership?
-whether object meets definition of the category
What is family resemblance?
-proposed idea to address problem that definitions often do not include all members of a category
How does family resemblance relate to categorization?
- things in a category resemble one another in another of ways
- allows for some variation within a category
Categorization may be based on _____
determining how similar an object is to some standard representation of a category
What is a prototype
- typical
- average representation of the typical member of cate
Prototype approach to categorization
-membership in a category is determined by comparing the object to a prototype that represents the category
What is an example of the prototype approach?
- not all birds are like robins, blue jays, or sparrows
- owls and penguins are also birds
Who is Rosch?
What was his experiment?
- prototype experiment
- S saw a category title (ex birds) + list of ~50 members of the category
- S asked to rate extent to which each member represented category title
What is high-prototypicality?
-category member closely resembles category prototype
-“tytpical” member
EX: “bird” = robin
What is low-prototypicality?
-category member does not closely resemble category prototype
EX: “bird” = penguin
What did Rosch and Mervis’s experiment test?
-test how well do good + poor examples of category compare to to other items within the category
How did Rosch and Mervis’s experiment work?
-for each common object, list as many characteristics/attributes
What does it mean when items have a large amount of overlap with characteristics of other items in the category?
-family resemblance of these items is high
EX: good examples of furniture = chair, sofa
poor examples = mirror
There is a strong positive relationship between _____ and _______
-prototypicality, family resemblance
What does low overlap between items mean?
-low family resemblance
What is the typicality effect?
-prototypical objects are processed preferentially
How are highly prototypical objects judge?
-more rapidly
EX: sentence verification technique
an apple is a fruit (y/n)
a pomegranate is a fruit (y/n)
What type of objects are named first?
-prototypical objects
What happens when asked to list as many objects in a category as possible?
-tend to list most prototypical members first
What are prototypical category members more affected by?
-a priming stimulus
How does a priming stimulus work?
- S heard the prime (ex: green)
- two seconds later: saw pair of colors side by side
- asked to press a key as quickly as possible if two were the same
-hearing “green” primes a highly prototypical green
What is the exemplar approach? (2)
- concept represented by multiple examples
(rather than a single averaged prototype) - examples are actual category members
How do you categorize according to the exemplar approach?
- compare new item to stored examples
- this approach can explain Rosch results
How is the exemplar approach similar/disimilar to the prototype view?
similar: representing a category is not defining it
different: representation is not abstract (descriptions of specific examples)
What effect does the exemplar approach explain?
-typicality effect
How does the exemplar approach take into account atypical cases?
- rather than comparing a penguin to an “average” bird
- remember that there are birds that don’t fly
Exemplars may work best for _____ categories
Prototypes may work best for _____ categories
- small
- larger
What does Rosch’s research indicate about categories?
- different levels of categories
- from general (“furniture”) to specific (“kitchen table”)
What are the three levels of categories?
- superordinate level (global level): “furniture”
- basic level: “table”
- subordinate level (or specific level): “kitchen table)
What is hierarchical organization?
-organization in which large/more general categories are divided into smaller, more specific categories
What was Rosch’s experiment about levels of categorization?
-S were asked to list as many features as they could that would be common to all/most objects in category
What is the result of going above basic level results?
large loss of information
What is the result of going below basic level?
little gain of information
The basic level is ____ special
psychologically
How is the guitar/fish example evidence that the basic-level is special?
- when S asked to name a guitar and a fish
- named them by their basic level name
- guitar rather than electric guitar (specific) or musical instrument (global)
- fish rather than trout/animal
How does culture paly into the results of Rosch’s experiment?
- there is a category level (called basic”
- reflects college undergraduates’ everyday experience
What was Coley, Medin + Atran’s experiment?
- asked both undergraduates + horticulturists to walk around campus
- name as specifically as possible 44 different plants
What was the result of the Coley, Medin + Atran experiment?
- 75% of undergrads used trees
- horticulturalists used “specific” categories like “oak”