When using views like circle plots or other similar visualization types, you'll often see that marks overlap, which can lead to obscuring part of the true story. Do you know for certain, just by looking, that there are only doctors in Intensive Care who are above average and only two below? Or could there be two or more circles exactly overlapping? One way of minimizing this is to click the Color shelf and add some transparency and a border to each circle. Another approach is a technique called jittering.
Various jittering techniques, such as using Index() or Random() functions, can be found by searching for jittering on the Tableau forums or Tableau jittering using a search engine.
Here is one approach that uses the Index() function, computed along Doctor, as a continuous field on Rows. Since Index is continuous (green), it defines an axis and causes the circles to spread out vertically. Now, you can more clearly see each individual mark and have higher confidence that the overlap is not obscuring the true picture of the data. You can use jittering techniques on many kinds of visualizations:
