d′etectable: Exploration

The table of outcomes lists the count of each trial outcome: Hits, Misses, False Alarms, and Correct Rejections. These counts are further summarized with Hit Rate, False Alarm rate, and overall Accuracy. You can modify any value, and any dependent values will update too.

In ROC space, performance is plotted as Hit Rate versus False Alarm Rate. All of the points with the same Sensitivity (d′) are illustrated with an Iso-Sensitivity Curve. All of the points with the same Bias (c) are illustrated with an Iso-Bias Curve. Moving the data point will cause the iso-curves to update as well.

The visual representation of the SDT model shows Sensitivity as the distance, d′, between the distributions. And it shows Bias as the location, c, of the threshold. The threshold divides the Signal + Noise Distribution into Hit and Miss areas and divides the Noise Distribution into Correct Rejection and False Alarm areas. Moving the distributions or the threshold adjusts d′ or c, respectively.

Across all three figures, the table of outcomes, ROC space, and the SDT model, adjustments to the performance or the model will be reflected immediately in the other figures as well.