These are the measures included in the downloadable Affymetrix Comparison
Analysis Data Files

Column Name	      Description
Affy ID		      Affymetrix Probe Set Identifier, which includes the Blattner
		      number and gene name when appropriate.
Stat Pairs	      The number of probe pairs in the probe set.
Stat Pairs Used	      The number of probe pairs in the probe set used in the
		      Detection call.
Signal		      A measure of the relative abundance of a transcript.
Detection	      A call indicating a Present (P), Absent (A), Marginal (M), or No
		      Call (NC) in transcript level of an experiment array.
Detection p-value     p-value that indicates the significance level of the
                      detection call.
Stat Common Pairs     The number of common probe pairs on two arrays
                      (experiment versus baseline) after saturation across
                      the probe set is determined.
Signal Log Ratio      The change in expression level for a transcript between a
                      baseline and an experiment array. This change is expressed 
                      as the log2 ratio. A log2 ratio of 1 is the same as a Fold
                      Change of 2.
Signal Log Ratio Low  The lower limit of the Signal Log Ratio within a 95%
                      confidence interval.
Signal Log Ratio High The upper limit of the Signal Log Ratio within a 95%
                      confidence interval.
Change                A call indicating an Increase (I), Marginal Increase (MI),
                      No Change (NC), Decrease (D), or Marginal Decrease (MD) in
                      transcript level between a baseline array and an 
                      experiment array.
Change p-value        p-value that indicates the significance level of the 
                      change call.
Descriptions	      contains information about the location in the genome 
                      each probe set represents along with a description of
		      what is found there.