A procedure for improving the display of bivariate data. If the variables are discrete, or if they are continuous, but the values have been rounded, then some value pairs may occur very often, but would be represented by a single point on a normal scatter diagram. A better impression of the data can be obtained by adding small random quantities to all values before plotting.
Jitter. The axes in the diagrams represent the numbers of tips reported by two tipping-bucket rain-gauges in September 2000. The jittered scatter diagram illustrates the amounts of rain for the 813 two-minute periods for which at least one gauge reported a tip. The inner diagram shows the corresponding 34-point scatter diagram.
Subjects: Probability and Statistics.