ROC Curve

Figure 1. ROC curve for Assay result
ROC curve for Assay result

The ROC curve is a visual index of the accuracy of the assay. The further the curve lies above the reference line, the more accurate the test. Here, the curve is difficult to see because it lies close to the vertical axis.

  1. To show more of the detail in the ROC curve, activate the plot by double clicking on it.
  2. In the Chart Editor window, activate the vertical axis by double clicking on it, then click the Scale tab in the Properties dialog box.
    Figure 2. Scale tab of the Properties dialog box; Y Axis
    Scale tab of the Properties dialog box; Y Axis
  3. Deselect Auto and type 0.9 as the custom minimum displayed value.
  4. Click Apply.
  5. In the Chart Editor window, activate the horizontal axis by double clicking on it, then click the Scale tab in the Properties dialog box.
    Figure 3. X Scale Axis dialog box
    X Scale Axis dialog box
  6. Deselect Auto and type 0.1 as the custom maximum displayed value.
  7. Click Apply, click Close, then close the Chart Editor window.
Figure 4. ROC Curve for Assay result, a closer look
ROC Curve for Assay result, a closer look

For a numerical summary, look below the graph at the Area Under the Curve table.

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