In Chapter 3, we discussed how to produce line plots to display the mean value of the two treatment groups by time. Another interesting data visualization would be to show the actual IOP values for all subjects by time in the same figure, which is known as a spaghetti plot. A spaghetti plot displays many line plots in the same figure. When many lines are drawn together in the same figure, the lines appear like noodles or spaghetti, hence the name. Spaghetti plots allow readers to see the data pattern over time for all subjects in a sample, and are good visualization tools to examine the overall response of all subjects over time.