The certainty level is one of Crystal Ball’s key statistics because it shows the probability of achieving values within a specific range (the certainty range). The certainty range for the forecast includes all trials between the certainty grabbers, triangles at each end of the certainty range. By default, Crystal Ball calculates the certainty level based on the entire range of forecast values, so the certainty level is the percentage of values in the certainty range compared to all values, expressed as a decimal.
You can determine the certainty level for a specific value range either by moving the certainty grabbers on the forecast chart or typing the certainty minimum and maximum in the text boxes. You can also type a certainty level in the Certainty text box to get a certainty range centered around the median.
When the certainty grabbers are at –Infinity and +Infinity, the certainty range includes every forecast value regardless of the size of the display range (and the certainty level is 100%). |
When you move the certainty grabbers, the certainty range changes and Crystal Ball recalculates the certainty level. When you type minimum and maximum values, Crystal Ball moves the certainty grabbers for you and recalculates the certainty level. When you type the certainty level in the Certainty text box, Crystal Ball moves the certainty grabbers to show you the value range for the certainty level you specified.