Bubble chart
The bubble diagram is a graphic representation of points, each with three dependent features, in a 2D surface. Two of the features are plotted like a scatter plot . The third characteristic is represented as the size of the bubble. Different colors can make the sizes of the bubbles even more clear.
This display form can be selected if the number and spacing of the data points do not result in excessive overlapping of the bubbles.
Applications
Web links
Commons : Bubble Charts - collection of images, videos and audio files