Problem 4
Matlin, Baddeley, Riegler, Sternberg
Article: Contextual Prerequisites for Understanding by Bransford and Johnson
SIMILARITY BASED MODELS
- Judging the similarity between the target object and some standard in long-term
memory
- Bottom-up (perceive) approach to categorization
1. TRADITIONAL VIEW
- According to this, items are classified into particular categories if they have
certain features or characteristics
- E.g. triangle is a closed 3-sided figures with an angle sum of 180, shapes that have
these characteristics are triangles, shapes that don’t are not
Limitations:
- It’s difficult to specify many concepts in terms of features that are both necessary
and sufficient
- Can’t explain the fact that our representations have a graded structure
- Categories don’t have clear cut boundaries, they have fuzzy boundaries
2. THE PROTOTYPE APPROACH
- Members of a category are evaluated based on their resemblance to other
members
- Members that have a high family resemblance are typical members and serve as
the standard, the most representative member: prototype
- Those with low family resemblance are less typical members
- A category has a graded structure, beginning with the most
representative/prototypical members and it continues onto the less typical
members
- The prototype approach is similarity-based because membership is determined
by an item’s similarity to the prototype
- Prototypes are abstracted through repeated experience with category members
- Prototypicality: the degree to which members are representative of their
category
Characteristics of prototypes:
- They are supplied as examples of a category – typicality effect
- They are judged more quickly than non-prototypes, after semantic priming
o Semantic priming effect: people respond faster to an item if it was
preceded by an item with similar meaning
- They share attributes in a family resemblance category
o Family resemblance: no single attribute is shared by all examples but each
example has at least one attribute in common
Pros:
- Explains the ability to from concepts of groups
- Can be applied to complex social relations
- Accounts cultural differences
, Limitations:
- People’s representations of categories and their characteristics are more complex
- Fails to capture that category representation is sensitive to context, what we view
as a typical category depends on how we think about it
- Problems when conjunction of 2 concepts are considered
- We store more specific encounters, we don’t abstract everything
3. THE EXEMPLAR APPROACH
- We represent categories in terms of examples or category exemplars
- There is no single representation of a category that is abstracted over time
- Our representations consist of every single encounter we’ve had with that
concept and we retrieve one of those encounters
- The exemplar approach is also similarity based: objects and events are assessed
in term of similarity to a standard but in this case the standard is a specific
example rather than a generalized categorization
- The standard will also depend on circumstances
- The typicality effect is not a problem: we’re more likely to retrieve the example
that’s been encoded more frequently
- The biasing effect of context is not a problem: a particular context can activate
certain exemplars, priming the retrieval
Pros: Takes individual differences into account
Limitations:
- In some circumstances, people do use abstracted representations constructed
from repeated encounters
- Cognitive economy: every single encounter with every single encounter can’t be
stored in memory
- Because we don’t have enough capacity, the theory can’t explain what we keep
as examples and what we erase
PROTOTYPE VS EXEMPLAR APPROACH
- both compare examples you just encoded to what you have already encoded
- both make similar predictions about semantic memory
- Prototype: a representation is a typical item of the category
- Exemplar: a representation is a collection of numerous specific members of a
category
- Exemplar: you don’t need an abstraction process to find a typical, which forces
you discard useful information about individual cases
- The exemplar may be more useful for a category with few members
- Prototype may be more useful for a category with numerous members
- Individual differences may be important in the way people represent categories
NAMING OBJECTS – LEVELS OF CATEGORIZATION:
- Concepts are organized into hierarchies: 3 levels:
- Superordinate categories at the top e.g. item of furniture
- Basic-level categories at the intermediate level e.g. chair
Matlin, Baddeley, Riegler, Sternberg
Article: Contextual Prerequisites for Understanding by Bransford and Johnson
SIMILARITY BASED MODELS
- Judging the similarity between the target object and some standard in long-term
memory
- Bottom-up (perceive) approach to categorization
1. TRADITIONAL VIEW
- According to this, items are classified into particular categories if they have
certain features or characteristics
- E.g. triangle is a closed 3-sided figures with an angle sum of 180, shapes that have
these characteristics are triangles, shapes that don’t are not
Limitations:
- It’s difficult to specify many concepts in terms of features that are both necessary
and sufficient
- Can’t explain the fact that our representations have a graded structure
- Categories don’t have clear cut boundaries, they have fuzzy boundaries
2. THE PROTOTYPE APPROACH
- Members of a category are evaluated based on their resemblance to other
members
- Members that have a high family resemblance are typical members and serve as
the standard, the most representative member: prototype
- Those with low family resemblance are less typical members
- A category has a graded structure, beginning with the most
representative/prototypical members and it continues onto the less typical
members
- The prototype approach is similarity-based because membership is determined
by an item’s similarity to the prototype
- Prototypes are abstracted through repeated experience with category members
- Prototypicality: the degree to which members are representative of their
category
Characteristics of prototypes:
- They are supplied as examples of a category – typicality effect
- They are judged more quickly than non-prototypes, after semantic priming
o Semantic priming effect: people respond faster to an item if it was
preceded by an item with similar meaning
- They share attributes in a family resemblance category
o Family resemblance: no single attribute is shared by all examples but each
example has at least one attribute in common
Pros:
- Explains the ability to from concepts of groups
- Can be applied to complex social relations
- Accounts cultural differences
, Limitations:
- People’s representations of categories and their characteristics are more complex
- Fails to capture that category representation is sensitive to context, what we view
as a typical category depends on how we think about it
- Problems when conjunction of 2 concepts are considered
- We store more specific encounters, we don’t abstract everything
3. THE EXEMPLAR APPROACH
- We represent categories in terms of examples or category exemplars
- There is no single representation of a category that is abstracted over time
- Our representations consist of every single encounter we’ve had with that
concept and we retrieve one of those encounters
- The exemplar approach is also similarity based: objects and events are assessed
in term of similarity to a standard but in this case the standard is a specific
example rather than a generalized categorization
- The standard will also depend on circumstances
- The typicality effect is not a problem: we’re more likely to retrieve the example
that’s been encoded more frequently
- The biasing effect of context is not a problem: a particular context can activate
certain exemplars, priming the retrieval
Pros: Takes individual differences into account
Limitations:
- In some circumstances, people do use abstracted representations constructed
from repeated encounters
- Cognitive economy: every single encounter with every single encounter can’t be
stored in memory
- Because we don’t have enough capacity, the theory can’t explain what we keep
as examples and what we erase
PROTOTYPE VS EXEMPLAR APPROACH
- both compare examples you just encoded to what you have already encoded
- both make similar predictions about semantic memory
- Prototype: a representation is a typical item of the category
- Exemplar: a representation is a collection of numerous specific members of a
category
- Exemplar: you don’t need an abstraction process to find a typical, which forces
you discard useful information about individual cases
- The exemplar may be more useful for a category with few members
- Prototype may be more useful for a category with numerous members
- Individual differences may be important in the way people represent categories
NAMING OBJECTS – LEVELS OF CATEGORIZATION:
- Concepts are organized into hierarchies: 3 levels:
- Superordinate categories at the top e.g. item of furniture
- Basic-level categories at the intermediate level e.g. chair
