Illustration of the methods used for the comparison of expression profiles from different platforms. A: Up/Down classification: The points A and B with very different ratios are both considered to reflect a common tendency; B: contingency table diagonal: The points A and B, with very similar ratios, end up in different classes; C: correlation coefficients: The solid line fits to the point cloud which has a significant correlation coefficient between X and Y. However, the dashed line (Y = X) is the expected line when both platforms show identical expression patterns.
van Ruissen et al. BMC Genomics 2005 6:91 doi:10.1186/1471-2164-6-91