Evaluating the reproducibility of t-statistics between spots using a standard t-test. Two subsets of Dataset 4 each contain three replicate arrays derived from identical biological experiments. (a) Comparison of t-statistics for each subset. Values greater than ± 500 are not shown. (b) Comparison of average logged ratios Mavg, which is the numerator of the t-statistic. (c) Comparison of the inverse of the standard deviation σM, which is in the denominator of the t-statistic. Values greater than 150 are not shown.