Sensitivity index

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.

A higher d' indicates that the signal can be more readily detected.

See also

• Receiver Operating Characteristic (R.O.C.)
• Summary Statistics

Reference

• Elementary Signal Detection Theory by Thomas D. Wickens (Ch.2, p.20).