of these studies did not provide a reference for their selection of filtering criteria or provide evidence that these strategies were helpful. Aston et al. [12] chose their fold-change threshold based on fold changes seen in previous microarray studies of post-mortem brain tissue, but technical variations between experiments can affect the distribution of signals. Stossi et al. [11] provided two references for their confidence score but neither of these gave a rationale for the calculation. Seo, et al. demonstrated that using the MAS5 detection p-value as a weighting factor in the distance measures for hierarchical clustering increased the ability to separate samples from biologically different groups [14].
