d'
From Wikipedia, the free encyclopedia
The sensitivity index or d' (pronounced 'dee-prime') is a statistic used in signal detection theory.
d' measures the separation between the means of the signal and noise distributions in units of the standard deviation of the noise distribution. An estimate of d' can be found from measurements of the hit rate and false-alarm rate. It is calculated as:
d' = z(hit rate) - z(false alarm rate), where function z() is the cumulative distribution function(cdf) of a gaussian probability distribution.
A higher d' indicates that the signal can be more readily detected.
[edit] See also
[edit] References
- Elementary Signal Detection Theory by Thomas D. Wickens (Ch.2, p.20).
[edit] External links
- Interactive signal detection theory tutorial including calculation of d'
