Figure 6

Maps of breast and pancreatic cancer mortality risks estimated by Poisson kriging and the corresponding kriging variance. For the two top maps, the fill color in each county represents the cancer mortality risk per 100,000 person-years estimated for the period 1970–1994; the class boundaries correspond to the deciles of the histogram of rates. The middle maps display the kriging variance computed using Equation (2); the class boundaries correspond to the deciles of the histogram of kriging variances. Bottom scattergrams illustrate the greater uncertainty of the risk estimated for sparsely populated counties.