Enter the hit rate and false alarm rate into the calculator to determine d prime.

## D Prime Formula

The following formula is used to calculate the D Prime (D') value.

D' = Z(Hit Rate) - Z(False Alarm Rate)

Variables:

- D' is the D Prime value Z(Hit Rate) is the Z score of the hit rate Z(False Alarm Rate) is the Z score of the false alarm rate

To calculate the D Prime value, first calculate the Z scores of the hit rate and the false alarm rate. The Z score is a measure of how many standard deviations an element is from the mean. Subtract the Z score of the false alarm rate from the Z score of the hit rate. The result is the D Prime value, which is a measure of signal detection ability.

## What is a D Prime?

D Prime (d') is a statistical measure used in signal detection theory to quantify the ability to distinguish between signal and noise. It represents the separation between the mean of the signal and the mean of the noise, divided by the standard deviation of the noise. A higher d' indicates a greater ability to differentiate signal from noise, while a lower d' suggests difficulty in distinguishing the two. It is commonly used in psychology, neuroscience, and other fields that involve decision making under uncertainty.

## How to Calculate D Prime?

The following steps outline how to calculate the D Prime value using the formula: D' = Z(Hit Rate) - Z(False Alarm Rate).

- First, determine the Z score of the hit rate.
- Next, determine the Z score of the false alarm rate.
- Next, subtract the Z score of the false alarm rate from the Z score of the hit rate.
- Finally, calculate the D Prime value.
- After inserting the variables and calculating the result, check your answer with the calculator above.

**Example Problem : **

Use the following variables as an example problem to test your knowledge.

D' is the D Prime value

Z(Hit Rate) is the Z score of the hit rate

Z(False Alarm Rate) is the Z score of the false alarm rate