similarity terms

Euclidian metric

The psychological distance metric between pairs of objects along integral perceptual dimensions, including all dimensions simultaneously in the distance calculation.

City block metric

The psychological distance metric between pairs of objects along separable perceptual dimensions, with each dimension included separately in the distance calculation.

Domain General

A construct that operates the same way in different domains, such as visual and auditory similarity.

Lexical decision task

A task where subjects must quickly decide if letter strings presented visually are words or non-words, with reaction time typically measured.

Minimality assumption

The assumption that nothing can be more similar to an object than it is to itself; maximum similarity leads to minimum distance.

Multidimensional scaling (MDS)

A computational technique that uses pairwise similarity ratings to visualize the psychological space of a set of objects.

Pairwise similarity

A similarity rating given between two pairs of objects.

Problem space

The arrangement of the current state, goal, obstacles, and operators in solving a problem, as defined by Newell and Simon (1972).

Separable dimensions

Perceptual dimensions or features that can be perceived separately, such as height and width.

Spreading activation

A theory suggesting that activation spreads from one active node in long term memory to other similar concepts or nodes.

Surface similarity

Similarity between two objects based on shared features at a surface level, like visual characteristics.

Symmetry Assumption

The assumption that the similarity between two objects does not change based on the order of comparison.

Triangle inequality assumption

The assumption that for three objects in psychological space, the additive distance between two pairs must be greater than or equal to the distance between any one pair.