Just an additional point on Jack's remark. It is not that the OLS fit is simply NOT SHOWN on a scatterplot when the slope is NOT SIGNIFICANT: the option to hide (or show) an OLS fit DOES NOT EVEN EXIST on the dialog box you get when you edit a scatterplot. Now, with this, I do have an issue! Why take this option away from the user? Perhaps it should default to NOT plotting an OLS line when the slope is insignificant BUT the option should be THERE when you edit the graph. John