Knowledge
Previous stored experiences used to make inferences.
What memory type is Knowledge?
It is semantic memory
Categories and Concepts
Groupings of things that go together to help us understand how the world is structured.
Categories
Sets of items that are perceptually, biologically, of functionally familiar.
Concepts
A mental representation of objects, ideas, or events.
The Common Sense Problem for A.I
Even implicit knowledge needs to be coded into a computer along with corresponding rules, which takes a long time to create.
Classical Approach to Categorization
Categories are clearly defined by sets of defining features that are both necessary and sufficient for category membership.
Problem with Classical Approach
It is nearly impossible to identify defining features for most categories.
Typicality Effect
We name typical objects first when asked about a category. Some items are more typical than others in a category.
Lexical Decision Tasks
Show participants a string of letter and determine if they are words or not.
Priming Effects
When participants identity a word faster after being exposed to a semantically related word.
3 Theories of Categorization
Prototype, Knowledge-Based, Exemplar.
Prototype Theory
Instead of relying on defining features, we consider which features are most likely among category types.
The Prototype
The average of all category members, the most typical member of a category.
Characteristic Features
Features that are likely to belong to a category members but not required for category membership.
Exemplar Theory
We store actual examples of items we have encountered in the past. Categorization occurs by comparing new items with ones in memory.
Knowledge-Based Theory
We rely on broad knowledge to explain category membership. It’s implicit.
Psychological Essentialism
All category members posses a fundamental essence that is unique to that category.
Risk of Essentialism
Can lead to stereotypes.
3 Category Hierarchies
Basic-Level, Subordinate, Superordinate.
Basic-Level Categories
Category that seems to be just right. Informative and Distinctive. Dog.
Subordinate Categories
Informative, but not distinctive. German Shepard. Specific.
Superordinate Categories
Distinctive but not informative. Animal. Simple.
Semantic Network Models
How we represent knowledge in the brain Stored as symbols.
