fuzzy set theory

an approach to set theory that allows gradations of membership in a set, instead of only assigning a 0 or a 1 that would indicate nonmembership or absolute membership, respectively. Some phenomena are more readily modeled with fuzzy set theory than conventional binary set theory. For example, in designation of a mental illness, fuzzy set theory may be employed to allow for cases in which individuals could be classified somewhere between having an absence and a full diagnosis of a particular condition.

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Psychology term of the day

May 3rd 2024

critical band

the band of frequencies in a masking noise that are effective in masking a tone of a given frequency (see auditory masking). The width of this band, in hertz (Hz), is the critical bandwidth. For example, in detecting a 1 kHz tone in white noise, only frequency components in the noise between 920 Hz and 1080 Hz contribute significantly to the masking: The critical band is from 920 Hz to 1080 Hz, and the critical bandwidth is 160 Hz. In psychoacoustics there are many manifestations of critical-band “filtering,” including spectral effects in loudness summation and monaural phase effects. See also auditory filter; frequency selectivity. [first described in 1940 by U.S. physicist Harvey Fletcher (1884–1981)]