signal: Parameter estimates for a signal detection study

In statpsych: Statistical Methods for Psychologists

Parameter estimates for a signal detection study

Description

Computes the hit rate, false alarm rate, d-prime, threshold, and bias for one participant (observer) in a Yes/No signal detection study. An equal-variance Gausian model is assumed. The parameter estimates are computed after adding .5 to the number of "Yes" responses in each condtion (the signal and noise conditions) and adding 1 to the number of signal trials and to the number of noise trails. In memory recognition studies, the observers is first presented with set of words or images to study, and is later presented with another set of words or images where some items are from the first list (old items) and some items are new items.

Usage

signal(f1, f2, n1, n2)

Arguments

f1	number of "Yes" responses in the stimulus (old item) trials
f2	number of "Yes" responses in the noise (new item) trials
n1	number of stimulus (or old item) trials
n2	number of noise (or new item) trials

Value

Returns a 1-row matrix. The columns are:

• HR - estimate of hit rate

• FAR - estimate of false alarm rate

• d-prime - estimate of d-prime

• Threshold - estimate of threshold (criterion)

• Bias - estimate of threshold minus d-prime/2

References

\insertRef

Wickens2002statpsych

Examples

signal(82, 46, 100, 100)

# Should return:
#         HR      FAR  d-prime  Threshold       Bias
#  0.8168317 0.460396 1.002793 0.09943603 -0.4019603

statpsych documentation built on April 4, 2025, 3:20 a.m.