Minimum Probability of Meeting the Target Date to Stop Adding New Centers Specify the minimum probability of meeting the deadline to stop adding new centers. New centers are added, one at a time, so long as the probability of meeting the deadline is less than this threshold value. This continues until the probability reaches the value specified and the number of new centers is sufficient for the recruitment to reach the target enrollment. To Specify a Minimum Probability: Either enter the desired value in the text field or move the slider to the right or to the left to change the value. Tip : To change the scale of the slider, right-click on the slider and select Rescale Slider from the pop-up menu. Change the upper or lower boundaries in the window that appears, to rescale the slider and click OK .