The extent of the damage caused by ozone. (Left) The spearman's rank correlation of log-intensities between arrays. The correlation between the log-intensities on the left 35 columns of the array on one microarray and another microarray is calculated for each pair of ozone-damaged arrays. These correlations are depicted in the boxplot. This is repeated for the undamaged arrays and also for the right 35 columns for both the damaged and undamaged arrays. Note that the exhaustive pairwise comparisons are not independent, but the plot illustrates the amount of information lost. (Right) Illustrating the increased variance associated with spots on ozone-affected arrays. After quantile normalization of the entire set of red-channel log-intensities, the mean and variance of observations of each spot were calculated firstly across the damaged arrays and secondly across the undamaged arrays. Note that the range of mean-intensities observed is lower in the damaged arrays.