Hello everybody, I am working on fitting some EXAFS of amorphous materials and have noticed an odd (in my mind) behavior when changing transform windows. I settled on a fit using all three k-weights and the Hanning transform window obtaining statistical parameters of R=0.0018 and chi_R=361. I decided to change the transform window to a Kaiser-Bessel to see what would happen. The refined parameters came out more or less the same, well within the error bars, with the Hanning windows having slightly smaller error bars. But my statistical parameters changed significantly to R=0.0022 and chi_R=89.354. It seems that this large change may be related to why we can't use the chi_R parameter to compare fits over different k-ranges, but I am not sure about that. Have other people seen this? I would guess it means that when looking for trends in different data sets, it is more important to be consistent, rather than which specific window type is used. Thanks, Brandon