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<body bgcolor = "#FFFFCC"><basefont face = "Arial"> |
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<h1>Data Adjustment: Percentage Cutoff</h1><h2>Parameter Information</h2> |
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<h2>Overview of Percentage Cutoff</h2> |
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The Percentage Cutoff data adjustment acts as a filter to remove genes |
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that have fewer than some percentage of valid values for the experiments under |
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study. It is common in microarray expression analysis to have some missing data, |
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however, if a particular gene has fewer than some percentage of it's values then the |
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gene can not be reliably compared to other genes. |
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This filtering method permits the |
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you to select a criteria such that any gene having fewer good values than the supplied |
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percentage will be removed from analyis runs. The history log will report the number |
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of genes that are remaining after the cuttof is applied using the "use percent cutoff" |
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menu option to enforce the cutoff. |
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<h2>Cutoff Parameter</h2> |
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This value, ranging from 0.0% to 100.0%, represents the percentage of valid |
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values that a gene is required to have in order to be allowed into analysis |
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algorithms. (e.g. 10 experiments loaded, cutoff criteria is 75%, if a gene |
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has only 6 valid values (60%) then that gene is not a candidate for analysis |
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while a gene having 8 valid values (80%) would be accepted.) |
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</body> |
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