from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The smallest mass of a fissionable material that will sustain a nuclear chain reaction at a constant level.
- n. The amount of matter needed to generate sufficient gravitational force to halt the current expansion of the universe.
- n. An amount or level needed for a specific result or new action to occur: "The sudden national uproar over drugs and drug abuse has reached politically critical mass in Washington” ( Tom Morganthau).
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. the amount of fissile material that is needed to support a self-sustaining nuclear chain reaction
- n. A quantity or amount required to trigger a phenomenon.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the minimum mass of fissionable material that can sustain a chain reaction
- n. the minimum amount (of something) required to start or maintain a venture
Sorry, no etymologies found.
Notice that a threshold occurs at the indi vidual level of analysis, whereas the critical mass operates at the system level.
For example, a new article of clothing becomes fashionable when a critical mass of social elites begins wearing it Grindereng, 1967; Crane, 1999.
Discontinuance of an interactive innovation by one individual may lead eventually to a critical mass of discontinuers, and then perhaps to complete rejection of a new idea such as e-mail by the entire system.
Granovetter 1978 provided an illustration of how the two-level phenomenon of individual thresholds and the system-level critical mass are interrelated:
Factors which act to slow the rate of adoption of an interactive innovation before the critical mass is reached (like network externali ties), then serve to speed up the adoption rate after the critical mass is attained (Wieber, 1992, 1995).
The likelihood of a relatively short time-to-take-off for a new product in a nation was higher if that product had already reached critical mass in neighboring countries.
Shermesh and Tellis 2002 determined the year in which the critical mass occurred by inspecting their data on the annual rate of adoption for each new product.
Marketing diffusion scholars have pioneered in identifying a new dependent variable for their analyses, the amount of time required to reach critical mass for a new product in a nation this variable is called “time-to-take-off”.
A small number of highly influential individuals who adopt a new idea may represent a much stronger critical mass than an equally sized number of individual adopters who have little influ ence.
A critical mass implies that reciprocal interdependence also occurs, in which early adopters are influenced by later adopters (and discontinuers and rejecters), as well as vice versa: “As users defect, the benefits to the remaining users will decrease and the costs increase, thus stimulating further defection” (Markus, 1987).