Synopsis: The Value of Circular Definitions

Methods from statistical physics and graph theory help uncover the structure of human language.
Synopsis figure
D. Levary et al., Phys. Rev. X (2012)

More than one reader has looked up a word in a dictionary, turned to a word used in the definition, only to be eventually pointed back to the original word in a loop of circular definitions. As annoying as this might sometimes be, such loops offer insights into the structure of a language and the expansion of its lexicon. David Levary, of Harvard University, and colleagues report in Physical Review X their use of methods from graph theory and statistical physics to study networks of words in dictionaries and show that creation of these loops is a fundamental mechanism in the growth of a language.

The authors looked at the words in a database called WordNet, treating them as nodes in a graph structure connected by directional links (that is, the link points to words used in the definition). Levary et al. show both theoretically and from watching how nodes are incorporated into the graph that new concepts can only be introduced by adding a loop to the network. They also discovered that words in a given loop often were introduced into the language at about the same time. When the dates of origin of words in a loop differ greatly, it typically indicates a fundamental change in a word’s meaning after its earlier introduction.

Levary et al. further found that new words preferentially attach to existing words with a large number of links pointing to them, a kind of linguistic “rich get richer” behavior. This matches our intuition that new words are defined in terms of well-used common words for better understandability. Taken together, the results suggest that such techniques from physics and graph theory could be a valuable forensic tool for uncovering the deeper workings of human communication and the evolution of language. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

Interdisciplinary PhysicsStatistical Physics

Previous Synopsis

Spintronics

Electrons that Take the Heat

Read More »

Related Articles

Synopsis: Straying from the Norm in Pedestrian Movements
Complex Systems

Synopsis: Straying from the Norm in Pedestrian Movements

Experiments tracking people as they walk down a corridor reveal universal behaviors that, if incorporated into models, could ensure safe flow in large crowds. Read More »

Synopsis: Number of Cycles Matters for a Quantum Engine
Statistical Physics

Synopsis: Number of Cycles Matters for a Quantum Engine

Theoretical calculations show that the performance of a quantum heat engine over several cycles can’t be judged by analyzing just a single cycle. Read More »

Focus: Grid Outages from Failures of Power Line Clusters
Complex Systems

Focus: Grid Outages from Failures of Power Line Clusters

Specific clusters within a network tend to fail consistently as part of large-scale network failures, such as those in electrical grids or airline transportation systems. Read More »

More Articles