See:-
Study of the Effectiveness of Shake Reduction in the Pentax K7
Pentax Shake Reduction Revisited
Just go read to figure out what they are doing and see if you agree with their findings and/or conclusions.
Do note that in order to obtain more meaningful and useful data and results, each test for a specific focal and shutter speed should be repeated for a number of times and some statistical analyses should be carried out for eliminating particular irregularities that could exist. It is because hand-shake is just something that could be somehow random, of which the magnitude could vary largely and be very different, even for the same person. In the above two tests, it seems that the testers have done something but it also seems that no further technical details are disclosed.
Besides, I think different subject/target distances could also affect the results but then all tests should be done at a particular distance per test above.
Last time, with the same concern and principle in mind, when I checked the SR performance of my K-x (against my 5D), I did carry out each test for three times (the target distance is also fixed, though):-
Pentax SR Performance Tested and Compared (K-x Against Canon IS)
I did no statistical analysis of any in the above as it is not meant to be a numerical analysis on the SR performance, but just a quick check and comparison of which I believe the shot pictures will tell.