What is categorisation in cognitive psychology?
Grouping similar entities (e.g., ‘birds’) based on shared features (shape, size, color).
What is the difference between a category and a concept?
Category = group of similar things (e.g., ‘dogs’); Concept = mental representation of it (e.g., your idea of a ‘dog’).
What are the three levels of category hierarchy?
- Superordinate (broad, e.g., ‘furniture’).
- Basic (most informative, e.g., ‘chair’).
- Subordinate (specific, e.g., ‘rocking chair’).
According to Rosch (1978), why are basic-level categories special?
They are:
- Named faster.
- Learned first.
- Have more shared attributes.
How does selective attention affect categorisation?
It focuses on relevant features (e.g., shape), ignoring irrelevant ones, reshaping perceived similarity.
What did Shepard et al. (1961) find about category learning?
Difficulty increases when irrelevant features distract from category-relevant attributes.
What is typicality in categorisation?
Some members (e.g., robins) are seen as better examples of a category than others (e.g., penguins).
How does family resemblance define categories?
No strict rules; members share overlapping features (e.g., ‘games’ vary but share fun/competition).
What factors influence category induction (Osherson et al., 1990)?
- Typicality of examples.
- Category size.
- Variability of instances.
How did categorisation bias the HMAS Sydney investigation?
Folk Devil Theory led to dismissing German accounts as lies due to stereotypes.
How was Zipf’s Law used to locate HMAS Sydney?
Analyzed word frequency in survivor reports to assess reliability, aiding wreck discovery (2008).
List 3 cognitive benefits of categorisation.
- Reduces environmental complexity.
- Informs behavior
- Organizing knowledge
What did Garner (1974) show about feature correlations?
Correlated features (e.g., size + color) speed up category learning.
What did Nosofsky (1986) find in transfer tests?
People internalize category structures based on learned feature weights.
How do goals influence categorisation?
They determine:<br></br>- Which features we attend to.<br></br>- Which categories we activate (e.g., ‘chair’ for office vs. home).
Three stages in the media’s reporting on folk devils:
- Symbolisation: the folk devil is portrayed in an oversimplified, easily recognizable, stereotyped fashion
- Exaggeration: the facts of the controversy surrounding the folk devil are distorted or simply made up
- Prediction: further immoral actions on the part of the folk devil are anticipated.
How does categorisation affect attention?
Focuses on salient/relevant features; Shepard, Hovland & Jenkins (1961): Simpler categories learned faster; Attention to one feature ‘stretches’ differences there and ‘compresses’ others
What’s the difference between feature salience and validity?
Salience: Grabs attention (bright colour, attractiveness); Validity: Truly determines category membership; They don’t always match; depends on task goals
What are the three main benefits of categorisation?
- Reduce complexity – organise info (e.g., colour categories);
- Guide behaviour – interpret features, infer missing info, understand affordances;
- Organise knowledge – hierarchical structures, family resemblance
What are superordinate, basic, and subordinate levels in categorisation?
Superordinate: Broad (e.g., furniture); Basic: Most informative, first learned (e.g., chair); Subordinate: Specific (e.g., rocking chair)
What is family resemblance in categories?
Members share overlapping features but not all are identical; More typical members share more features → recognised faster, generalise better
How did ‘social categorisation’ affect the HMAS Sydney mystery?
Australians categorized the German survivors as the ““enemy
What was the main finding of the Shepard, Hovland & Jenkins (1961) study on category learning?
Simple categories are easier to learn.
Categories defined by a single feature (Type I) were learned fastest
Why are simple categories easier to learn, according to the lecture?
Because attention is a limited resource.
We learn to ““stretch”” our attention to the relevant feature, making differences on that dimension easier to see,
while ““shrinking”” our attention to irrelevant features.
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Lecture 2 Categorization26
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Lecture 1 Introduction20
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Lecture 4 ANOVA27
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Lecture 3 Learning30
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Lecture 5 Attention - Origin, early & late selection27
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Lecture 6 Attention14
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Lecture 7 Attention in Space and Time27
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Lecture 8 Object based attention21
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Lecture 9 Memory44
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Lecture 10a False Memory59
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Lecture 1163
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Lecture 12 Judgement and Decision Making27
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