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                                                                    EXHIBIT 15.1


                         ACKNOWLEDGEMENT OF INDEPENDENT
                          CERTIFIED PUBLIC ACCOUNTANTS
                 REGARDING INDEPENDENT AUDITORS' REVIEW REPORT


The Board of Directors
SPSS Inc.:

With respect to this joint proxy statement/prospectus, we acknowledge our
awareness of the incorporation by reference therein of our reports dated
May 10, 2000, August 4, 2000 and November 1, 2000 related to our reviews of
interim financial information.

Pursuant to Rule 436(c) under the Securities Act of 1933, such reports are not
considered part of a registration statement prepared or certified by an
accountant or a report prepared or certified by an accountant within the
meaning of sections 7 and 11 of the Act.




Chicago, Illinois
December 15, 2000