PSYC 213 Chapter Notes - Chapter 8: Complex Network, Eleanor Rosch, Uncorrelated Random Variables
28 May 2018
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Chapter 8: Concepts
Classical Approach
• Concept: general category into which we can sort any number of particular instances
o Something qualifies within a concept because the common basic attributes, regardless of
differences in values of those attributes
o i.e. is printed, has a cover & pages no matter that is on cover/pages
• Conjunctive concept: simple conjunction of 2+ attributes
• Disjunctive concept: 1 of 2+ possible sets of attributes
o i.e. Canadian citizenship is disjunctive since can be acquired in many ways (born in
Canada, born abroad to Canadian parent, or becoming naturalized citizen)
• Relational concept: relationship between attributes determines the class to which event is
assigned
o i.e. marriage is relationship between two people, sister, above, left, etc.
• Show people cards, each of which is or isn't an instance of a particular concept
o i.e. if conjunctive concept is black & square, then any card with both these attributes =
positive instance
o If not, then negative instance
• Criterial attribute: attribute that is required in order for something to quality as an instance of a
concept
o Occurs in all positive instances
• Abstraction: process of including recurring attributes & excluding non-recurring ones
Concept Formation Tasks
• Investigate strategy used by participants to acquire simple conjunctive concept
• Selection task: concept formation task in which experiment shows you a card from an opened
set, and tells you whether is a positive instance of the concept
o Then must select instances (cards) and the experimenter will tell you if positive or
negative instances
o Must try to figure out the concept
• Can select cards such that differ from the first positive instance by only one feature
o Conservative focusing: concept formation strategy where actively formulate hypotheses
and select instances to test hypothesis by focusing on one attribute at a time
• Focus gambling: concept formation strategy in which select instances that vary from first
positive instance by more than on attribute
• Simultaneous scanning involves keeping in mind all possible hypotheses & trying to eliminate
as many as possible with each instance selection
o High load placed on memory
• Successive scanning: formulate single hypothesis & test it by selecting instances until the
correct hypothesis emerges
o Less demanding
Reception Strategies
• Reception task: concept formation task in which instances presented to participants are
chosen by experimenter
o As opposed to selection task where participant selected instances
• Wholist strategy: Initially hypothesize that all attributes are member of the concept
o If next positive instance is inconsistent with that hypothesis, then form new one based on
commonality with old hypothesis
o Concept formation strategy used in reception tasks
• Partist strategy: initially hypothesize that only some of the attributes are members of the
concept
o Retain until receive disconfirming evidence, and then change hypothesis to make it
consistent with all positive instances
o Heavy load on memory since must recall all previous instances
Criticism of Classical Concept Research
• Similar to game mastermind where one player uses coloured pegs to create a code that other
player must guess by proposing possible solutions & receiving feedback on accuracy
o Would be selection task since participant proposing instances
• Criticism: real-world concepts much more complex
o Lack ecological validity
Learning Complex Rules
• Finite state grammar is a diagram connecting numbers with specific directions of link
between them (similar to railroad station)
o Paths between numbers are labelled with letters
o Set of rules for generating strings of letters
• Task where asked to distinguish between strings of letters consistent with grammar (positive
instances) and inconsistent
• Explore distinction between implicit & explicit learning --intentionally or not
o Implicit: show participants some letter strings and ask them to memorize as many as
possible without telling them that they follow certain rules
o Explicit: tell participants that letter strings follow certain rules & ask them to figure out
what those rules are
• Then showed them letter strings, and asked them to identify those with same structure as first
set had seen
o Implicit condition led to significant amount of rule-learning
o Sometimes even better performance than explicit learning
o Unconsciously abstracting of structure of the grammar
o Acquiring knowledge unconsciously and efficiently
• Learning implicitly leads to a vague sense of what is consistent and what is not, without being
able to specifically identify the grammatical structure
o Better performance = better ability to say what have learned
o Knowledge is tacit: know it but not able to say exactly what it is
