Number of Posterior Samples per Markov Chain Specify the number of posterior samples to generate. To Specify the Number of Posterior Samples: 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 that appears, to rescale the slider and click OK.