Related Experiment Video
Updated: Jun 19, 2026

08:12
A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments
Published on: March 1, 2022
Exemplar similarity and rule application
Ulrike Hahn1, Mercè Prat-Sala, Emmanuel M Pothos
1School of Psychology, Cardiff University, Wales CF10 3AT, UK. hahnu@cardiff.ac.uk
Cognition
|October 10, 2009
Summary
Instance similarity influences rule application, affecting errors and reaction times even with perfect rules. These effects appear mandatory and beyond conscious control in categorization tasks.
Area of Science:
- Cognitive Psychology
- Decision Making
- Machine Learning
Background:
- Explicit rule learning is a cornerstone of cognitive processes.
- Understanding how instance similarity impacts rule application is crucial for explaining categorization behavior.
- Previous research has not fully elucidated the automaticity of similarity effects in rule-based categorization.
Purpose of the Study:
- To investigate the impact of instance similarity on the application of explicit rules.
- To determine if similarity effects are mandatory or strategic.
- To explore the role of rule-irrelevant features in similarity-based categorization.
Main Methods:
- Four experiments were conducted to examine the effects of instance similarity.
- Participants were given simple, explicit, and perfectly predictive rules.
- Similarity was manipulated using rule-irrelevant features, and its effect on error patterns and reaction times was measured.
Main Results:
- Instance similarity significantly affected error patterns and reaction times.
- These effects persisted even when similarity was based on irrelevant features and attention to similarity was detrimental.
- Performance was impaired when participants focused on exemplar similarity.
Conclusions:
- Similarity effects in rule application appear to be mandatory, non-strategic, and not consciously controlled.
- These findings suggest that similarity influences categorization automatically and pervasively.
- The results have implications for understanding human categorization and potentially for designing artificial intelligence systems.
Related Concept Videos
Causes of Similarity-Dissimilarity Effect
The similarity-dissimilarity effect, a fundamental concept in social psychology, explains how interpersonal similarities and differences influence attraction and social interactions. This effect is supported by three key psychological perspectives: balance theory, social comparison theory, and consensual validation.Balance Theory and Cognitive ConsistencyBalance theory, developed by Fritz Heider, posits that individuals seek cognitive consistency in their relationships. When two people share...
The Representativeness Heuristic
The representative heuristic describes a biased way of thinking, in which you unintentionally stereotype someone or something. For example, you may assume that your professors spend their free time reading books and engaging in intellectual conversation, because the idea of them spending their time playing volleyball or visiting an amusement park does not fit in with your stereotypes of professors.
Kirchoff's Rules: Application
Kirchhoff's rules quantify the current flowing through a circuit and the voltage variations around the loop in a circuit. Applying Kirchhoff's rules generates a set of linear equations that allow us to find the unknown values in circuits. These may be currents, voltages, or resistances.
When applying Kirchhoff's first rule, the junction rule, label the current in each branch and decide its direction. If the chosen direction is wrong, it will have the correct magnitude, although the current will...
When applying Kirchhoff's first rule, the junction rule, label the current in each branch and decide its direction. If the chosen direction is wrong, it will have the correct magnitude, although the current will...
Principle of Equivalence
According to Albert Einstein (1897-1955), free-falling and feeling weightless are intrinsically linked. If a person were in free-fall under gravity, for example, diving towards the Earth from an airplane, they would feel completely weightless. Similarly, a person descending in a lift may feel partially weightless. Broadly speaking, it is assumed that an object in a uniform gravitational field and an object undergoing constant acceleration in the absence of gravity are under the same...
Woodward–Hoffmann Selection Rules and Microscopic Reversibility
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
Convergent Evolution
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.The structures that arise from convergent evolution are called analogous structures. They are similar in function even if they are dissimilar in structure. Further, structures can be analogous while also...

