Between-Group Overlay Jitter Specify the amount to shift between groups of spectra on the y -axis in the data overlay plot . This option is useful in cases where many spectra overlap, but note the y -axis values will no longer be the same as the input data. To Specify Between-Group Overlay Jitter: Type a value into the text box. The value must be in the range of 0 to 10000 , inclusive.