conceptual knowledge
knowledge that enables us to recognize objects and events to make inferences about their properties
concept
mental representation that is used for a variety of cognitive functions.
categories
include all possible examples of a particular concept
categorization
is the process by which things are placed into groups called categories
why categories are useful
-help us deal w novel info (i.e., individual cases not previously encountered)
- can act as ‘pointers to knowledge’ , placeholder, label, etc
-provides a wealth of general info about terms and allows us to identify special characteristics , properties, etc
definitional approach
the theory that we can determine if an object belongs to a category by checking if it meets a specific set of necessary and sufficient criteria.
family resemblance
members of a category are related by an overlapping network of similarities, rather than by a single, defining feature common to all members.
allows for some variation within a category
prototypes
average representations of the typical member of a category. ex. an apple would constitute as a prototype for the fruit category
prototype approach
people categorize new information by comparing it to a mental representation of the most typical member of a category
high prototypicality
category member closely resembles category prototype . ex. for ‘bird’, robin is high prototypicality
low prototypicality
category member does not closely resemble category prototype . ‘atypical’ member for category. e.g., for ‘bird’, penguin is low prototypicality
Smith et al. (1974) - typicality effect
used the sentence verification technique and asked participants to evaluate whether various statements are true
found high prototypicality objects judged more rapidly
-prototypical objects are preferentially processed
typicality effect
the finding that people judge more typical examples of a category faster and more easily than atypical ones.
naming effect
people are more likely to list some objects than others when asked to name objects in a category
priming effect
presentation of one stimulus affects responses to a stimulus that follows
exemplar approach
individuals classify new items by comparing them to specific examples (exemplars) stored in memory
exemplar approach vs prototype approach
The prototype approach proposes we categorize by comparing a new stimulus to an abstract, idealized “average” member of a category, while the exemplar approach suggests we categorize by comparing it to a memory of specific, individual examples we have encountered.
- prototypes may work best earlier on in learning , and /or for larger categories
-exemplars may work best later on in learning (when expertise is developed), and/or for larger categories
hierarchical organization
how people categorize and structure information into a hierarchy of concepts and sub-concepts
global (superordinate) level
the highest, most inclusive level in a hierarchical categorization scheme.
ex. animal
basic level
intermediate level is psychologically privileged and is typically the most natural and frequently used in everyday language.
ex. dog
specific (subordinate) level
This is the most specific level of categorization.
ex. golden retriever
Rosch et al. (1976) -hierarchical organization
asked participants to list as many properties as they could related to various objects.
-going above the ‘basic’ level (to global) resulted in a large loss of info, going ‘below’ (to specific) resulted in little gain of info
- implies that basic level strikes a good balance
-also asked to name pictures of various objects, participants tended to use basic levels. found that objects were responded to more quickly when the basic level was used
effects of expertise - Tanaka and Taylor (1991)
found that experts used more specific categories , while novices used more basic.
semantic networks
concepts are arranged in networks that represent the way concept are organized in the mind
categories/ concepts are represented by a node
related concepts are linked
