Exhibit 8.2


                      [Foley, Hoag & Eliot LLP Letterhead]
December____, 2001




NetGenesis Corp.
One Alewife Center
Cambridge, Massachusetts 02140

Re: Proposed Merger of Red Sox Acquisition Corp. and NetGenesis Corp.

Ladies and Gentlemen:

         We have acted as counsel to NetGenesis Corp., a Delaware corporation
(the "Target") in connection with the proposed merger (the "Merger") of Red Sox
Acquisition Corp. (the "Merger Sub"), a wholly-owned first tier subsidiary of
SPSS Inc., a Delaware corporation (the "Buyer"), in accordance with the
Agreement and Plan of Merger by and among the Target, the Merger Sub and the
Buyer made as of October 28, 2001 (the "Agreement"). Capitalized terms used but
not defined herein shall have the respective meanings ascribed to them in the
Agreement.

         We have examined the law and such papers, including the Agreement, as
deemed necessary to render the opinion expressed below. As to questions of fact
material to our opinion we have relied on representations of the Target, the
Merger Sub and the Buyer contained in letters addressed to us and attached to
this letter (the "Letters of Representation"), without undertaking to verify the
same by independent investigation; upon representations set forth in the
Agreement (including the Exhibits); and upon such other documents pertaining to
the Merger as we have deemed appropriate and necessary.

         In our examination we have assumed that (i) the Merger will be
consummated in accordance with the terms of the Agreement; (ii) each entity that
is a party to any of the documents (the "Documents") described in the preceding
paragraphs has been duly organized under the laws of its state or country of
organization, is validly existing and in good standing under such laws, and is
duly qualified and in good standing in each jurisdiction in which it is required
to be qualified to engage in the transactions contemplated by the Documents;
(iii) each such entity has full power, authority, capacity and legal right to
enter into and perform the terms of the Documents and the transactions
contemplated thereby; (iv) the copies or originals of the Documents furnished to
us are authentic (if originals) or accurate (if copies), those that are
contracts or instruments are enforceable and effective in accordance with their
terms against all parties thereto, and all signatures are genuine; (v) any
representations made in the Documents are, and will continue to be, true and
complete, and no default exists under any of the Documents; (vi) the business
and affairs of each of the entities that is a party to any of the Documents will
be conducted in accordance with the Documents and all relevant laws; (vii) no
actions will be taken, no change in any of the Documents will occur, and no
other events will occur, after the date hereof, that would have the effect of
altering the facts, Documents or assumptions upon which this opinion is based;
and (viii) the business reasons for the Merger will

constitute a valid business purpose, within the meaning of Treasury Regulation
section 1.368-1(b) and (c), for the Merger.

         The opinion rendered herein is based upon the provisions of the
Internal Revenue Code of 1986, as amended (the "Code"), Treasury Department
temporary and final regulations, judicial decisions, and rulings and
administrative interpretations of the Internal Revenue Service, as each of the
foregoing exists on the date hereof. The opinion rendered below is not binding
on the Internal Revenue Service or a court of law, and no assurance can be given
that legislative or administrative action or judicial decisions that differ from
the opinion rendered below will not be forthcoming. Any such differences could
be retroactive to transactions or business operations prior to such action or
decisions.

         We express no opinion as to the federal income tax consequences other
than that described below, if any, or as to the effect of the Merger on other
transactions, or as to any state, local or foreign income or other tax
consequences with respect to the Merger.

         Based on the foregoing, we are of opinion, as of the date hereof and
under existing law, that the Merger will constitute a reorganization within the
meaning of section 368(a) of the Code.

         We undertake no responsibility to update or supplement our opinion. We
are furnishing this letter to you solely in support of the information set forth
under the heading "Material Federal Income Tax Consequences" in the Registration
Statement. We hereby consent to the filing of this opinion with the Securities
and Exchange Commission as an exhibit to the Registration Statement and to the
reference to our firm under such heading in the Registration Statement. In
giving such consent, we do not thereby admit that we are in the category of
persons whose consent is required under Section 7 of the Securities Act of 1933,
as amended. This letter is not to be used, circulated, quoted or otherwise
referred to for any other purpose without our prior written consent.


                                        Very truly yours,



                                        Foley, Hoag & Eliot LLP


                                        By: ____________________
                                                 A Partner