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Percog: Category
Perception and Cognition - Categorisation
Question | Answer |
---|---|
Name 5 benefits of categorisation. | 1. Reduce complexity of environment 2. Ease of identification 3. Reduce need for constant learning 4. Allow appropriate actions to be taken 5. Enables structure of knnowledge |
What are the 3 levels of natural category? | Superordinate level. Basic level. Subordinate level. |
Elaborate superordinate level. | Highest level of hierarchy. Category member little in common. Largest. |
Elaborate basic level. | Members share many feature. Few feature in common with members of other basic level. More differentiated. First learned and most used in language. People identify fastest here unless experts. Can be represented by prototypes (average of category member). |
Elaborate subordinate level. | Share lots of features with one another. Even with members of other subordinate categories. Smallest. |
What is the typicality effect? | It is how well a category member represents the category. It is due to family resemblance. More typical member = more in common with other members. Least typical member = fewer attributes in common. |
Name four categorisation models. | Prototype. Exemplar. Feature-frequency. Theory-based categorisation. |
What is the Prototype model? | People create a prototype that is a good representation of category. |
Prototype model - Prototype rule | Create mental representation of prototypical member of category Compute similarity between prototypes and novel stimulus Assign to category that has most similar prototype |
Advantage and Disadvantage of prototype model? | Advantage - Few comparisons needed Disadvantage - Cannot handle noncontinuous attribute (marital status) |
What is the Exemplar model? | Patterns are classified by comparing similarity to category examples |
Exemplar model - Nearest neighbour rule |