This document outlines 5 steps to create a graphical method for recalling test statistics: 1. Draw and label a 2x2 chart with true positive, true negative, false positive, and false negative. 2. Add down and up arrows labeling sensitivity and specificity. 3. Reverse the arrow heads to label false positive and negative rates. 4. Add horizontal arrows labeling positive and negative predictive values. 5. The final diagram allows recalling various test statistics like likelihood ratios, odds ratio, and accuracy.

1. A Graphical Method for Recalling
Test Statistics
Step 1 - Draw & Label Your 2X2 Chart
Dz No DzTest
(+)
(-)
Tp
Tn
Fp
Fn

2. Step 2 - Put in a down-going arrow & an up-going Arrow
Dz No DzTest
(+)
(-)
Tp
Tn
Fp
Fn
Tp
Tp + Fn
Tn
Tn + Fp
Sensitivity
Specificity
Starting at origin of arrow place label at top of your formula and than below division line place label at bottom of arrow + label at point of arrow
True (+) Rate
True (-) Rate
Type I Error
Type II Error

3. Step 3 - Reverse the Direction of the Arrow Heads
Dz No DzTest
(+)
(-)
Tp
Tn
Fp
Fn
Fn
Tp + Fn
Fp
Tn + Fp
False (-) Rate
False (+) Rate
Starting at origin of arrow place label at top of your formula and than below division line place label at bottom of arrow + label at point of arrow

4. Step 4 - Put in Horizontal Arrow Heads
Dz No DzTest
(+)
(-)
Tp
Tn
Fp
Fn
Tp
Tp + Fp
PPV
Tn
Tn + Fn
NPV
Starting at origin of arrow place label at top of your formula and than below division line place label at bottom of arrow + label at point of arrow

5. Step 5 - Final Diagram
Dz No DzTest
(+)
(-)
Tp
Tn
Fp
Fn
Fn
Tp + Fn
Fp
Tn + Fp
FNR
FPR
LR(+)=
TPR
FPR
LR(-)=
TNR
FNR
Odds Ratio=
LR(+)
LR(-)
Tp
Tp + Fn
TPR
Tn
Tn + Fp
TNR
Tp
Tp + Fp
PPV
Tn
Tn + Fn
NPV
Accuracy=
Tp+Tn
Tp + Fn + Tn + Fp