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                                                                   EXHIBIT 10.33


                            STOCK PURCHASE AGREEMENT


     THIS STOCK PURCHASE AGREEMENT (the "Agreement"), dated as of October 22,
2001 (the "Effective Date"), is entered into by and between SPSS INC., a
Delaware corporation, with headquarters located at 233 South Wacker Drive,
Chicago, Illinois 60606 ("SPSS"), and America Online, Inc., a Delaware
corporation, with headquarters located at 22000 AOL Way, Dulles, Virginia 20166
("Buyer").

                              W I T N E S S E T H:

     WHEREAS, SPSS and Buyer are entering into that certain Strategic Online
Research Services Agreement dated of even date herewith (the "Research Services
Agreement");

     WHEREAS, pursuant to the Research Services Agreement, SPSS is issuing to
Buyer such number of newly issued, unregistered shares of SPSS Common Stock,
$.01 par value per share (the "Common Stock"), as more fully described herein;
and

     WHEREAS, SPSS and Buyer are executing and delivering this Agreement in
accordance with and in reliance upon an exemption from securities registration
afforded, inter alia, by Rule 506 under Regulation D ("Regulation D") as
promulgated by the United States Securities and Exchange Commission (the
"Commission") under the Securities Act of 1933, as amended (the "1933 Act" or
the "Act"), and/or Section 4(2) of the 1933 Act.

     NOW THEREFORE, in consideration of the premises and the mutual covenants
contained herein and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties agree as follows:

     1.   ISSUANCE OF SHARES; SHARE CONSIDERATION.

     a.   AGREEMENT TO ACQUIRE. The parties hereto acknowledge and agree that,
in consideration of (i) the services being provided pursuant to the Research
Services Agreement and (ii) the exclusivity and marketing support provided by
Buyer described therein, SPSS shall, among other things, issue, and Buyer or
Buyer's designee shall acquire, that number of shares of Common Stock calculated
in accordance with the provisions of Section 1.b below (collectively, the
"Shares"). In the event that any of the calculations performed in Section 1.b
below yields an aggregate number of Shares owned by Buyer (calculated at the
time of each such issuance) which is greater than 4.9% of SPSS's issued and
outstanding shares of Common Stock, the number of such shares of Common Stock
will be reduced to equal 4.9% of SPSS's issued and outstanding shares of Common
Stock as of the Effective Date or the date of the applicable Subsequent Share
Issuance (as defined in Section 1.b(ii)hereof), and SPSS will pay Buyer the Gap
Amount (pursuant to and as defined in the Research Services Agreement) in
immediately available funds to an account designated by Buyer. Notwithstanding
anything to the contrary contained herein, fractional shares shall not be
issued. In lieu of fractional shares, the Initial Share Consideration and/or any
Subsequent Share Consideration (as each is defined in Section 1.b(i) and Section
1.b(ii), respectively) for the shares of Common Stock acquired by Buyer
hereunder shall be adjusted such that only whole shares shall be issued
hereunder.

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     b.   ISSUANCE AND DELIVERY OF SHARES. The Shares shall be issued and
delivered to Buyer according to the following schedule:

          (i)   On the Effective Date, SPSS shall deliver that number of shares
                of Common Stock (the "Initial Shares") up to, but not to exceed,
                4.9% of the issued and outstanding shares of Common Stock (the
                "Initial Share Issuance") calculable by dividing THREE MILLION
                AND NO/100 dollars ($3,000,000) (subject to adjustment to
                prevent the issuance of fractional shares) (the "Initial Share
                Consideration") by the average of the closing prices of SPSS
                Common Stock, as quoted on the NASDAQ National Market ("NASDAQ")
                for the five (5) trading days preceding the Effective Date (the
                "Initial Share Consideration Closing Price"). In the event that
                the closing price of SPSS Common Stock, as quoted on the NASDAQ
                on the day (as it applies to this Section 1.b.(i), the
                "Preceding Date") preceding the date the Registration Statement
                required by Section 4.a(i)(A) becomes effective (the
                "Registration Statement Effective Date Closing Price"), is less
                than the Initial Share Consideration Closing Price, then at
                SPSS's option with notice of SPSS's election to be given to
                Buyer on the day preceding the Preceding Date, (A) SPSS shall
                deliver to Buyer a cash amount, in immediately available funds
                to an account designated by Buyer, equal to the difference
                between the Initial Share Consideration and the fair market
                value of the number of shares of SPSS Common Stock SPSS would
                have issued to Buyer had the Initial Share Consideration Closing
                Price equaled the Registration Statement Effective Date Closing
                Price, or (B) SPSS shall issue to Buyer that number of shares
                equal to the difference between (y) the number of shares of SPSS
                Common Stock SPSS would have issued to Buyer had the Initial
                Share Consideration Closing Price equaled the Registration
                Statement Effective Date Closing Price and (z) the number of
                Initial Shares actually issued to Buyer on the Effective Date,
                provided, however, that any shares of SPSS Common Stock to be
                issued to Buyer pursuant to this sentence shall be included
                within the Registration Statement required by Section 4.a(i)(A)
                hereof, or (C) any combination thereof. In the event that the
                Registration Statement Effective Date Closing Price is greater
                than the Initial Share Consideration Closing Price, then, at
                Buyer's option with notice of Buyer's election to be given to
                SPSS on the day preceding the Preceding Date, Buyer shall
                deliver to SPSS (A) a cash amount, in immediately available
                funds to an account designated by SPSS, equal to the difference
                between fair market value of the number of shares of SPSS Common
                Stock SPSS would have issued to Buyer had the Initial Share
                Consideration Closing Price equaled the Registration Statement
                Effective Date Closing Price and the Initial Share
                Consideration, or (B) that number of shares of SPSS Common Stock
                equal to the difference between the number of Initial Shares
                determined by dividing the Initial Share Consideration by the
                Initial Share Consideration Closing Price and the number of
                Initial Shares determined by dividing the Initial Share
                Consideration by the Registration Statement Effective Date
                Closing Price, provided, however, that SPSS is only obligated to
                make


                                       2
<PAGE>

                effective the registration of Buyer's resale of that number of
                shares of SPSS Common Stock held by Buyer following the
                application of Buyer's delivery obligations set forth in this
                sentence, or (C) any combination thereof.

          (ii)  On each of the first, second and third anniversary dates of the
                Effective Date, SPSS shall deliver that number of shares of
                Common Stock (the "Subsequent Shares") up to, but not to exceed,
                in the aggregate taken together with all other shares of Common
                Stock held by Buyer, 4.9% of the issued and outstanding shares
                of Common Stock on the date of issuance (each hereinafter
                referred to individually as a "Subsequent Share Issuance" and
                collectively as the "Subsequent Share Issuances") calculable by
                dividing THREE MILLION AND NO/100 DOLLARS ($3,000,000) (subject
                to adjustment to prevent the issuance of fractional shares)
                (each hereinafter referred to as a "Subsequent Share
                Consideration") by the average of the closing prices of SPSS
                Common Stock, as quoted on the NASDAQ for the five (5) trading
                days preceding each applicable anniversary date of the Effective
                Date (each such price a "Subsequent Share Consideration Closing
                Price"). In the event that the closing price of SPSS Common
                Stock, as quoted on the NASDAQ on the day (as it applies to this
                Section 1.b(ii), the "Subsequent Preceding Date") preceding the
                applicable date that any Registration Statement required by
                Section 4.a(i)(B) becomes effective (each such price a
                "Subsequent Registration Statement Effective Date Closing
                Price"), is less than the corresponding Subsequent Share
                Consideration Closing Price, then at SPSS's option with notice
                of SPSS's election to be given to Buyer on the day preceding the
                Subsequent Preceding Date, (A) SPSS shall deliver to Buyer a
                cash amount, in immediately available funds to an account
                designated by Buyer, equal to the difference between the
                Subsequent Share Consideration and the fair market value of the
                number of shares of SPSS Common Stock SPSS would have issued to
                Buyer had the applicable Subsequent Share Consideration Closing
                Price equaled the corresponding Subsequent Registration
                Statement Effective Date Closing Price, or (B) SPSS shall issue
                to Buyer that number of shares equal to the difference between
                (y) the number of shares of SPSS Common Stock SPSS would have
                issued to Buyer had the applicable Subsequent Share
                Consideration Closing Price equaled the corresponding Subsequent
                Registration Statement Effective Date Closing Price and (z) the
                number of Subsequent Shares actually issued to Buyer on the
                applicable date of such Subsequent Share Issuance, provided,
                however, that any shares of SPSS Common Stock to be issued to
                Buyer pursuant to this sentence shall be included within the
                applicable Registration Statement required by Section 4.a(i)(B)
                hereof, or (C) any combination thereof. In the event that any
                Subsequent Registration Statement Effective Date Closing Price
                is greater than any corresponding Subsequent Share Consideration
                Closing Price, then, at Buyer's option with notice of Buyer's
                election to be given to SPSS on the day preceding the Subsequent
                Preceding Date, Buyer shall deliver


                                       3
<PAGE>

                to SPSS (A) a cash amount, in immediately available funds to an
                account designated by SPSS, equal to the difference between the
                fair market value of the number of shares of SPSS Common Stock
                SPSS would have issued to Buyer had any applicable Subsequent
                Share Consideration Closing Price equaled the corresponding
                Subsequent Registration Statement Effective Date Closing Price
                and the Subsequent Share Consideration, or (B) that number of
                shares of SPSS Common Stock equal to the difference between the
                number of Subsequent Shares determined by dividing the
                Subsequent Share Consideration by the Subsequent Share
                Consideration Closing Price and the number of Subsequent Shares
                determined by dividing the Subsequent Share Consideration by the
                Subsequent Registration Statement Effective Date Closing Price,
                provided, however, that SPSS is only obligated to make effective
                the registration of Buyer's resale of that number of shares of
                SPSS Common Stock held by Buyer following the application of
                Buyer's delivery obligations set forth in this sentence, or (C)
                any combination thereof.

          (iii) Any monetary payments to be made by either party pursuant to
                this Section 1.b shall be made within two (2) business days of
                the date that the Registration Statement required by Section
                4.a(i) hereof becomes effective.

          (iv)  Notwithstanding the provisions of Sections 1.b.(i) and (ii)
                above, SPSS shall have no obligation to issue and deliver, and
                Buyer shall have no right to receive, any portion of the Shares
                if the Research Services Agreement has been terminated prior to
                the date on which the Initial Share Issuance or any Subsequent
                Share Issuance occurs. In addition, in the event a dispute
                occurs between SPSS and Buyer with respect to the terms and
                provisions of the Research Services Agreement, SPSS shall have
                no obligation to issue and deliver, and Buyer shall have no
                right to receive, any portion of the Shares that are to be
                issued to Buyer on the Effective Date or on the date of any
                Subsequent Share Issuance, until such disputes have been
                mutually resolved by the parties. Further, the six (6) month and
                two (2) month time period set forth in Sections 4.a(i)(A) and
                4.a(i)(B) below, pursuant to which SPSS is obligated to make
                effective Registration Statement(s) for Buyer's resale of any
                portion of the issued Shares, shall each be extended, as
                applicable, by the corresponding number of days that it takes
                for the parties to resolve any disputes that arise as described
                in the immediately preceding sentence. Subject to the provisions
                of Section 4 hereof, the Shares, when issued and delivered to
                Buyer, shall be unencumbered and freely tradable by Buyer.


                                       4
<PAGE>

     2.   BUYER REPRESENTATIONS AND WARRANTIES.

     Buyer represents and warrants to SPSS as follows:

     a.   Without limiting Buyer's right to sell any portion of the Shares
pursuant to a Registration Statement registering the sale of such Shares on
account of Buyer, Buyer acknowledges that the sale and issuance of the Shares to
be delivered to Buyer on the Effective Date or on the date of any applicable
Subsequent Share Issuance may not have been registered pursuant to the 1933 Act
and that, to the extent the sale and issuance of the Shares by SPSS to Buyer is
not subject to an effective Registration Statement, Buyer is acquiring the
Shares for its own account for investment only and not with a view towards the
resale or distribution of any part thereof and not with a view to or for sale in
connection with any distribution thereof.

     b.   Buyer is (i) an "accredited investor" as that term is defined in Rule
501 of Regulation D as presently in effect, (ii) experienced in making
investments of the kind described in this Agreement and the related documents,
(iii) able, by reason of the business and financial experience of its officers
(if an entity) and/or professional advisors (who are not affiliated with or
compensated in any way by SPSS or any of its affiliates or selling agents), to
protect its own interests in connection with the transactions described in this
Agreement, and the related documents, and (iv) able to afford the entire loss of
its investment in the Shares.

     c.   Buyer understands that the Shares to be issued and delivered on the
Effective Date or on the date of any applicable Subsequent Share Issuance may
not have been registered under the 1933 Act, or any applicable state securities
laws. Therefore, Buyer shall not sell or offer to sell all or any portion of the
Shares except pursuant to registration of the Shares under the 1933 Act or an
exemption from registration requirements of United States federal and state
securities laws and in compliance with all applicable state securities laws.

     d.   Buyer understands that the Shares to be issued and delivered to Buyer
on the Effective Date or on the date of any applicable Subsequent Share Issuance
may be offered and sold to it in reliance on specific exemptions from the
registration requirements of United States federal and state securities laws and
that SPSS is relying upon the truth and accuracy of, and Buyer's compliance
with, the representations, warranties, agreements, acknowledgments and
understandings of Buyer set forth herein in order to determine the availability
of such exemptions and the eligibility of Buyer to acquire any portion of the
Shares.

     e.   Buyer and its advisors have been furnished with all materials relating
to the business, finances and operations of SPSS and materials relating to the
offer and sale of the Shares which have been requested by Buyer. Buyer and its
advisors have been afforded the opportunity to ask questions of SPSS and have
received complete and satisfactory answers to any such inquiries.

     f.   Buyer understands that no United States federal or state agency or any
other government or governmental agency has passed on or made any recommendation
or endorsement of the Shares.


                                       5
<PAGE>

     g.   This Agreement has been duly and validly authorized, executed and
delivered on behalf of Buyer and is a valid and binding agreement of Buyer
enforceable in accordance with its terms, subject as to enforceability to
general principles of equity and to bankruptcy, insolvency, moratorium and other
similar laws affecting the enforcement of creditors' rights generally.

     3.   SPSS REPRESENTATIONS AND WARRANTIES.

     SPSS represents and warrants to Buyer that:

     a.   SPSS STATUS. SPSS is a corporation duly organized, validly existing
and in good standing under the laws of the State of Delaware, and has the
requisite corporate power to own its properties and to carry on its business as
presently conducted and as proposed to be conducted by it. SPSS is duly
qualified or licensed to do business and in good standing in each jurisdiction
in which the nature of its business or properties makes such qualification or
licensing necessary, except where the failure to so qualify or be licensed would
not have a material adverse effect on the business, financial condition, results
of operations, assets, liabilities or prospects of SPSS.

     b.   AUTHORIZED AND OUTSTANDING STOCK; ISSUANCE OF SECURITIES.

          (i)   The authorized capital stock of SPSS (immediately prior to the
                Initial Share Issuance) consists of Fifty Million (50,000,000)
                shares of Common Stock, $0.01 par value per share, 14,107,400 of
                which were issued and outstanding as of September 30, 2001. As
                of September 30, 2001, SPSS has granted options to acquire
                4,991,790 shares of SPSS Common Stock upon the exercise thereof
                under SPSS's Third Amended and Restated 1995 Equity Incentive
                Plan, 1999 Employee Equity Incentive Plan and Amended 1991 Stock
                Option Plan.

          (ii)  The offer, issuance and sale of the Shares pursuant to this
                Agreement have been duly authorized by all necessary corporate
                action on the part of SPSS. The Initial Shares, when so issued,
                sold and delivered against payment therefor in accordance with
                the provisions of this Agreement, and any Subsequent Shares,
                when issued in accordance with the terms of this Agreement, will
                be duly and validly issued, fully paid and nonassessable. None
                of the offer, issuance or sale of the Shares is subject to, or
                in violation of, any preemptive rights, rights of first refusal,
                or other rights to purchase such stock, pursuant to any
                agreement or commitment of SPSS.

     c.   BINDING AGREEMENT. This Agreement and the transactions contemplated
hereby have been duly and validly authorized by SPSS (including any actions to
be taken by SPSS's officers, directors and stockholders), this Agreement has
been duly executed and delivered by SPSS and this Agreement, when executed and
delivered by SPSS, will be a valid and binding agreement of SPSS enforceable in
accordance with its terms, subject as to enforceability to general principles of
equity and to bankruptcy, insolvency, moratorium, and other similar laws
affecting the enforcement of creditors' rights generally.


                                       6
<PAGE>

     d.   NON-CONTRAVENTION. The execution, delivery and performance of this
Agreement by SPSS, the issuance of the Shares, and the consummation by SPSS of
the transactions contemplated by this Agreement do not and will not conflict
with or result in a material breach by SPSS of any of the terms or provisions
of, or constitute a default under (i) SPSS's Certificate of Incorporation or
by-laws, (ii) any agreement, contract, lease, license, equipment lease,
indenture, mortgage, deed of trust, or other material agreement (oral or
written) or instrument to which SPSS is a party or by which it or any of its
properties or assets are bound, (iii) any existing applicable law, rule, or
regulation or any applicable decree or judgment, except any such law, rule,
regulation, decree or judgment which would not have a material adverse effect on
the transactions contemplated herein, or (iv) any judgment, writ, decree, order,
law, statute, ordinance, rule or regulation applicable to SPSS or any of its
properties or assets, except any such conflict, breach or default which would
not have a material adverse effect on the transactions contemplated herein.

     e.   APPROVALS. No authorization, approval or consent of any court,
governmental body, regulatory agency, self-regulatory organization, or stock
exchange or market is required to be obtained by SPSS in connection with the
execution and delivery of this Agreement or the consummation of any of the
transactions contemplated hereby, including, but not limited to, the issuance
and sale of the Shares to Buyer as contemplated by this Agreement, except such
authorizations, approvals and consents that have been obtained. Based upon the
representations made by Buyer in Section 2 of this Agreement, the offer and sale
of the Shares to Buyer will be in compliance with applicable federal and state
securities laws.

     f.   COMMISSION DOCUMENTS; FINANCIAL INFORMATION.

          (i)   SPSS has made all filings with the Commission required under the
                Securities Exchange Act of 1934, as amended (the "Exchange
                Act"), or the 1933 Act, on a timely basis. SPSS has previously
                made available to Buyer complete and accurate copies, as amended
                or supplemented through the date hereof, of the following forms
                filed with the Commission: (A) Form 10-Q under the Exchange Act
                for the period ended March 31, 2001, (B) Form 10-Q under the
                Exchange Act filed for the period ended June 30, 2001, (C) Form
                10-K, as amended, for the fiscal year ended December 31, 2000,
                and (D) each Form 8-K filed during fiscal year 2001 (such
                reports, including any Exchange Act reports to be filed by the
                Company after the date hereof, are collectively referred to
                herein as the "Company Reports"). As of their respective dates,
                the Company Reports did not contain any untrue statement of a
                material fact or omit to state a material fact required to be
                stated therein or necessary to make the statements therein, in
                light of the circumstances under which they were made, not
                misleading.

          (ii)  The audited financial statements and unaudited interim financial
                statements of SPSS included in the Company Reports (A) comply as
                to form in all material respects with applicable accounting
                requirements and the published rules and regulations of the
                Commission with respect thereto, (B) have been prepared in
                accordance with United States generally accepted accounting
                principles ("GAAP") applied on a consistent basis throughout the
                periods covered thereby (except as may be


                                       7
<PAGE>

                indicated therein or in the notes thereto, and in the case of
                quarterly financial statements, as permitted by Form 10-Q under
                the Exchange Act), and (C) fairly presented in all material
                respects (subject, in the case of the unaudited interim
                financial statements, to normal, year-end audit adjustments,
                none of which will be material) the consolidated financial
                condition, results of operations and cash flows of SPSS as of
                the respective dates thereof and for the periods referred to
                therein.

     g.   ABSENCE OF CERTAIN CHANGES. Except as disclosed in the Company
Reports, since June 30, 2001, there has been no change, event or effect that is
materially adverse to the assets, business, financial condition or the results
of operations of SPSS, except for those changes, events and effects that are
disclosed in the Company Reports.

     h.   LITIGATION. Except as otherwise set forth on Schedule 4(h), there is
no action, suit or legal proceeding, or governmental inquiry or investigation,
pending against SPSS, or, to SPSS's knowledge, threatened against SPSS which (a)
questions the validity of this Agreement or the right of SPSS to enter into this
Agreement or perform any of its obligations hereunder or (b) is reasonably
likely to have a material adverse effect on the assets, business, financial
condition or results of operations of SPSS.

     i.   UNDISCLOSED LIABILITIES. SPSS has no liability (whether absolute,
accrued, contingent or otherwise), except for (i) liabilities reflected in the
Company Reports, (ii) liabilities which have arisen since June 30, 2001 in the
ordinary course of business and that are consistent with past experience and
(iii) contractual liabilities incurred in the ordinary course of business.

     j.   PROPRIETARY ASSETS.

          (i)   Except as otherwise set forth on Schedule 3(j), SPSS (A) owns or
                has the right to use all Proprietary Assets (as defined below)
                used in or necessary for its business as currently conducted and
                as proposed to be conducted, free and clear of all material
                liens, and all such Proprietary Assets are sufficient to enable
                SPSS to conduct its business in the manner in which such
                business has been and is being conducted free from liabilities
                or valid claims of infringement or misappropriation by third
                parties; and (B) has taken reasonable and customary measures and
                precautions necessary to protect and maintain the
                confidentiality and secrecy of all its Proprietary Assets
                (except the Proprietary Assets whose value would be unimpaired
                by public disclosure) and otherwise to maintain and protect the
                value of all its Proprietary Assets.

          (ii)  Except where such infringement, misappropriation or unlawful use
                has not had or could not reasonably be expected to have a
                material adverse effect on the assets, business, financial
                condition or the results of operation of SPSS, SPSS is not
                infringing, misappropriating or making any unlawful use of any
                Proprietary Asset owned or used by any other individual,
                corporation, partnership, limited liability company, joint
                venture, trust or unincorporated organization or a government or
                agency or political subdivision thereof (each, a "Person"); and
                no claims or notices (in writing


                                       8
<PAGE>

                or otherwise) with respect to Proprietary Assets have been
                communicated to SPSS: (A) to the effect that the manufacture,
                sale, license or use of any Proprietary Assets as now used or
                currently offered or proposed for use or sale by SPSS infringes
                or potentially infringes, or constitutes a misappropriation or
                unlawful use of any patent, trademark, trade name, service mark,
                copyright, maskwork, trade secret or other proprietary or
                intellectual property right of a third party, or (B) challenging
                the ownership or validity of any of the rights of SPSS to or its
                interest in such Proprietary Assets. SPSS has not received any
                notice to the effect that any patents or registered trademarks,
                service marks or copyrights held by SPSS are invalid or not
                subsisting. To SPSS's knowledge, no other Person is infringing,
                misappropriating or making any unlawful use of, and no
                Proprietary Asset owned or used by any other Person infringes or
                conflicts with, any Proprietary Asset used in or pertaining to
                the business of SPSS.

          (iii) SPSS has not licensed any of its Proprietary Assets to any
                Person on an exclusive basis or entered into any covenant not to
                compete or contract limiting its ability to sell its products or
                services in any market or geographical area or with any Person
                other than restrictions in a license agreement that are typical
                of those granted in the ordinary course of business in its
                industry.

          (iv)  As used herein, the term "Proprietary Assets" means: (A) any
                patent, patent application, trademark (whether registered or
                unregistered), trademark application, trade name, fictitious
                business name, service mark (whether registered or
                unregistered), service mark application, copyright (whether
                registered or unregistered), copyright application, maskwork,
                maskwork application, trade secret, know-how, customer list,
                franchise, system, computer software, computer program, source
                code, databases, invention, design, blueprint, engineering
                drawing, proprietary product, technology, or other proprietary
                or intellectual property right or intangible asset, in any
                medium in whole or in part; and (B) any right to use or exploit
                any of the foregoing.

     k.   COMPLIANCE WITH LAWS. SPSS is not (i) subject to the terms or
provisions of any material judgment, decree, order, writ or injunction or (ii)
in violation of any terms or provisions of any laws, rules, or regulations,
except where such violations do not and are not likely to have a material
adverse effect on the assets, business, financial condition or results of
operations of SPSS or as disclosed in the Company Reports.

     4.   SECURITIES MATTERS

     a.   REGISTRATION OF SPSS COMMON STOCK.

          (i)   (A)   SPSS will file one or more Registration Statements on Form
                      S-3 (together with all amendments and supplements thereto,
                      including post-effective amendments, and all materials
                      incorporated by reference or deemed to be incorporated by
                      reference therein) under


                                       9
<PAGE>

                      the 1933 Act and the rules and regulations promulgated
                      thereunder, and shall make all commercially reasonable
                      efforts to cause the Registration Statement to be declared
                      effective by the Commission and to maintain the
                      effectiveness of the Registration Statement, for the
                      registration of the resale of the Initial Shares by Buyer,
                      which such Registration Statement(s) shall be effective
                      within six (6) months of the Effective Date; provided,
                      however, that in no event shall SPSS cause the
                      Registration Statement to be declared effective by the
                      Commission within five (5) trading days of an announcement
                      or other event relating to SPSS which has had a negative
                      effect on SPSS's trading price during such five (5) day
                      period.

                (B)   Prior to the date of each Subsequent Share Issuance, SPSS
                      will file one or more Registration Statements on Form S-3
                      or another form available for registration (together with
                      all amendments and supplements thereto, including
                      post-effective amendments, and all materials incorporated
                      by reference or deemed to be incorporated by reference
                      therein) under the 1933 Act and the rules and regulations
                      promulgated thereunder, and shall make all commercially
                      reasonable efforts to cause the Registration Statements to
                      be declared effective by the Commission and to maintain
                      the effectiveness of the Registration Statements, for the
                      registration of the resale of the applicable portion of
                      the Subsequent Shares by Buyer, which such Registration
                      Statements shall be effective within two (2) months of the
                      applicable Subsequent Share Issuance; provided, however,
                      that in no event shall SPSS cause the Registration
                      Statement to be declared effective by the Commission
                      within five (5) trading days of an announcement or other
                      event relating to SPSS which has had a negative effect on
                      SPSS's trading price during such five (5) day period.

          (ii)  If and to the extent necessary, Buyer shall cooperate with SPSS
                in connection with the registration of the Initial Shares issued
                on the Effective Date and the registration of the Subsequent
                Shares to be issued on the date of each Subsequent Share
                Issuance, and shall provide such information and execute such
                documents as SPSS shall reasonably request in connection with
                such registration.

          (iii) (A)   In the event that the resale of the Initial Shares has not
                      been registered under an effective Registration Statement
                      within six (6) months of the Effective Date, SPSS shall be
                      obligated to pay Buyer Three Million Dollars ($3,000,000)
                      (the "Initial Payment") in accordance with the provisions
                      of Section 4.a.(iv) below.



                                       10
<PAGE>

                (B)   In the event that the resale of any portion of the
                      Subsequent Shares has not been registered under an
                      effective Registration Statement within two (2) months of
                      the date of any Subsequent Share Issuance, SPSS shall be
                      obligated to pay Buyer Three Million Dollars ($3,000,000)
                      (any such payment a `Subsequent Payment") in immediately
                      available funds to an account designated by Buyer in lieu
                      of the Subsequent Shares to be issued to Buyer on the date
                      of such Subsequent Share Issuance.

          (iv)  (A)   With respect to SPSS's obligation to pay Buyer any
                      monetary amounts in accordance with the provisions of
                      Section 4.a.(iii) above, as of the Effective Date, SPSS
                      will deliver to Buyer a letter of credit in the aggregate
                      of $3,000,000, in the form attached hereto as Exhibit A
                      and made a part hereof, within two (2) business days of
                      the Effective Date. In the event SPSS fails to deliver the
                      letter of credit to Buyer within two (2) business days of
                      the Effective Date, Buyer shall have the right to either
                      (a) automatically terminate the Agreement or (b) instruct
                      SPSS to pay $3,000,000 to Buyer in immediately available
                      U.S. funds to an account designated by Buyer, which such
                      payment shall be made by SPSS within one (1) business day
                      of Buyer's notification to SPSS of its election under this
                      sentence of Section 4.a.(iv)(A). SPSS shall only be
                      obligated to maintain the letter of credit until SPSS has
                      effectively registered the resale of the Initial Shares
                      within the six (6) month period following the Effective
                      Date.

                (B)   Notwithstanding the foregoing, in the event SPSS has not
                      registered the resale of the Initial Shares as
                      contemplated in Section 4.a.(iii)(A) above or registered
                      the resale of any portion of the Subsequent Shares as
                      contemplated by Section 4.a(iii)(B) above, SPSS shall be
                      under no obligation to deliver the Initial Payment or any
                      Subsequent Payment, as the case may be, to Buyer until
                      Buyer has provided written confirmation evidencing the
                      transfer of all of the Initial Shares or the applicable
                      portion of the Subsequent Shares, as the case may be, from
                      its broker-dealer to SPSS's transfer agent in accordance
                      with the instructions provided by SPSS to Buyer in order
                      to enable Buyer to effect properly such transfer.

          (v)   In the event that SPSS fails to maintain the effectiveness of
                any Registration Statement pursuant to which Buyer has the right
                to resell any of the Initial Shares or any portion of the
                Subsequent Shares, as the case may be, Buyer shall have the
                right to require SPSS to purchase that portion of the Initial
                Shares or any portion of the Subsequent Shares, as the case may
                be, which Buyer then currently owns at a per share purchase
                price equal to the closing price of SPSS Common Stock, as quoted
                on the NASDAQ on the date Buyer attempts to resell such Initial
                Shares or the applicable portion of the Subsequent Shares, as
                the case may be.


                                       11
<PAGE>

          (vi)  SPSS shall be obligated to deliver to Buyer the Initial Payment,
                any Subsequent Payment and any purchase price calculated in
                accordance with the provisions of Section 4.a(v) above, as the
                case may be, within two (2) business days of the date on which
                such right accrued, provided that Buyer has tendered written
                confirmation evidencing the transfer of the applicable portion
                of the Shares in accordance with the provisions of Section
                4.a(iv)(B) above.

     b.   REGISTRATION EXPENSES. SPSS shall be responsible for and shall pay all
fees, costs and expenses incurred by it relating to the registration of the
issuance of the Shares by SPSS and/or the resale thereof by Buyer, including
without limitation, all Commission and NASDAQ registration and filing fees, and
all fees and expenses of compliance by SPSS with the federal securities laws or
any applicable state blue sky laws, but not including (i) any fees and expenses
of Buyer's counsel or other expenses of Buyer incurred in connection with the
execution and delivery of this Agreement or the Research Services Agreement or
(except as provided above) the resale of all or any portion of the Shares or
pursuant to Section 4.a(iv)(A) above, and (ii) underwriters' fees or expenses,
broker's costs, commissions and other similar disposition costs associated with
the SPSS Common Stock owned by Buyer.

     c.   POTENTIAL RESTRICTIONS. Buyer understands and agrees, as follows:

          (i)   The Shares may not be subject to a Registration Statement under
                the 1933 Act, and may be issued pursuant to exemptions from
                registration under the 1933 Act which exemptions depend, among
                other things, on the bona fide nature of Buyer's investment
                intent.

          (ii)  Buyer shall not transfer the Shares except in compliance with
                the provisions of the 1933 Act. Any proposed transferee of any
                of the Shares shall agree to take and hold such securities upon
                the conditions set forth in Section 4(c)(iii) hereof.

          (iii) Until a Registration Statement registering the resale of the
                Shares by Buyer is declared effective, such Shares may not be
                offered, sold or transferred in the absence of an effective
                Registration Statement or an exemption therefrom or in
                contravention of the terms and conditions of this Agreement.
                When the Registration Statement registering the resale of the
                Initial Shares and any portion of the Subsequent Shares, as the
                case may be, is declared effective by the Commission, that
                portion of the Shares subject to the effective Registration
                Statement shall be unencumbered and freely tradable by Buyer.

          (iv)  Unless a Registration Statement under the 1933 Act covering
                transactions in the Shares has been declared effective by the
                Commission and such Registration Statement remains effective at
                the time of transfer, each transferee of Shares shall agree in
                writing to comply in all respects with the provisions of this
                Section 4(c). Prior to any proposed transfer of any such Shares,
                the holder thereof shall give written notice to SPSS of such


                                       12
<PAGE>

                holder's intention to effect such transfer and shall comply with
                the requirements set forth in the balance of this section. Each
                such notice shall describe the manner and circumstances of the
                proposed transfer in reasonable detail, and shall be accompanied
                by (1) a "no action" letter from the Commission to the effect
                that the distribution of such Shares without registration will
                not result in a recommendation by the staff of the Commission
                that action be taken with respect thereto, or (2) such other
                showing reasonably satisfactory to SPSS and its counsel that the
                proposed transfer of such Shares may be effected without
                registration under the 1933 Act, including, but not limited to,
                Rule 144 eligibility, whereupon the holder of such Initial
                Shares shall be entitled to transfer such securities in
                accordance with the terms of the notice delivered by the holder
                to SPSS. None of Buyer nor any transferee of all or any portion
                of the Shares shall be required to comply with the provisions of
                this Section 4(c) from and after the date on which a
                Registration Statement registering the resale of the Shares
                shall be declared effective by the Commission.

     d.   INDEMNIFICATION. If and to the extent that Buyer shall transfer any of
the Initial Shares or any portion of the Subsequent Shares, as the case may be,
pursuant to a Registration Statement as provided above:

          (i)   SPSS will indemnify and hold harmless Buyer, any underwriter (as
                defined in the 1933 Act) for Buyer and each person, if any, who
                controls Buyer or underwriter within the meaning of the 1933 Act
                or the Exchange Act against any losses, claims, damages, or
                liabilities (joint or several) to which they may become subject
                under the 1933 Act, the Exchange Act or other federal or state
                law, insofar as such losses, claims, damages, or liabilities (or
                actions in respect thereof) arise out of or are based upon any
                of the following statements, omissions or violations
                (collectively a "Violation"): (i) any untrue statement or
                alleged untrue statement of a material fact contained in such
                Registration Statement, including any preliminary prospectus or
                final prospectus contained therein or any amendments or
                supplements thereto, (ii) the omission or alleged omission to
                state therein a material fact required to be stated therein, or
                necessary to make the statements therein not misleading, or
                (iii) any violation or alleged violation by SPSS of the 1933
                Act, the Exchange Act, any state securities law or any rule or
                regulation promulgated under the 1933 Act, the Exchange Act or
                any state securities law; and SPSS will pay to Buyer,
                underwriter or controlling person, any and all legal or other
                expenses reasonably incurred by them in connection with
                investigating or defending any such loss, claim, damage,
                liability, or action; provided, however, that the indemnity
                agreement contained in this subsection 4(d)(i) shall not apply
                to amounts paid in settlement of any such loss, claim, damage,
                liability, or action if such settlement is effected without the
                consent of SPSS, which consent shall not be unreasonably
                withheld or delayed, nor shall SPSS be liable in any such case
                for any such loss, claim, damage, liability, or action to the
                extent that it arises out of or is based upon a


                                       13
<PAGE>

                Violation which occurs in reliance upon and in conformity with
                written information furnished by Buyer any controlling person of
                Buyer expressly for use in connection with such registration.

          (ii)  Buyer will indemnify and hold harmless SPSS, each of its
                directors, each of its officers who has signed the Registration
                Statement, each person, if any, who controls SPSS within the
                meaning of the 1933 Act, any underwriter, and any controlling
                person of any such underwriter, against any losses, claims,
                damages, or liabilities (joint or several) to which any of the
                foregoing persons may become subject, under the 1933 Act, the
                Exchange Act or other federal or state law, insofar as such
                losses, claims, damages, or liabilities (or actions in respect
                thereto) arise out of or are based upon any Violation, in each
                case to the extent (and only to the extent) that such Violation
                occurs in reliance upon and in conformity with written
                information furnished by Buyer expressly for use in connection
                with such registration, and Buyer will pay, as incurred, any
                legal or other expenses reasonably incurred by any person
                intended to be indemnified pursuant to this subsection 4(d)(ii),
                in connection with investigating or defending any such loss,
                claim, damage, liability, or action; provided, however, that the
                indemnity agreement contained in this subsection 4(d)(ii) shall
                not apply to amounts paid in settlement of any such loss, claim,
                damage, liability or action if such settlement is effected
                without the consent of Buyer, which consent shall not be
                unreasonably withheld or delayed.

          (iii) Promptly after receipt by an indemnified party under this
                Section 4(d) of notice of any claim, demand or the commencement
                of any action (including any governmental action), such
                indemnified party will, if a claim in respect thereof is to be
                made against any indemnifying party under this Section 4(d),
                deliver to the indemnifying party a written notice of the claim,
                demand or action and the indemnifying party shall have the right
                to participate in, and, to the extent the indemnifying party so
                desires, jointly with any other indemnifying party similarly
                noticed, to assume the defense thereof with counsel mutually
                satisfactory to the parties; provided, however, that an
                indemnified party (together with all other indemnified parties
                which may be represented without conflict by one counsel) shall
                have the right to retain one separate counsel and local counsel,
                with the fees and expenses to be paid by the indemnifying party,
                if representation of such indemnified party by the counsel
                retained by the indemnifying party would be inappropriate due to
                a conflict of interests between such indemnified party and any
                other party represented by such counsel in such proceeding. The
                failure to deliver written notice to the indemnifying party
                within a reasonable time of receipt by the indemnified party of
                notice of such claim, demand or commencement of any such action,
                if prejudicial to its ability to defend such action, shall
                relieve such indemnifying party of any liability to the
                indemnified party under this Section 4(d).


                                       14
<PAGE>

          (iv)  If the indemnification provided for in this Section 4(d) from
                the indemnifying party is unavailable to an indemnified party
                hereunder in respect of any losses, claims, damages, liabilities
                or expenses referred to therein, then the indemnifying party, in
                lieu of indemnifying such indemnified party, shall contribute to
                the amount paid or payable by such indemnified party as a result
                of such losses, claims, damages, liabilities or expenses in such
                proportion as is appropriate to reflect the relative fault of
                the indemnifying party and indemnified party in connection with
                the actions which resulted in such losses, claims, damages,
                liabilities or expenses, as well as any other relevant equitable
                considerations. The relative faults of such indemnifying party
                and indemnified party shall be determined by reference to, among
                other things, whether any action in question, including any
                untrue or alleged untrue statement of a material fact or
                omission or alleged omission to state a material fact, has been
                made by, or relates to information supplied by, such
                indemnifying party or indemnified party, and the parties'
                relative intent, knowledge, access to information and
                opportunity to correct or prevent such action. The amount paid
                or payable by a party as a result of the losses, claims,
                damages, liabilities and expenses referred to above shall be
                deemed to include any fees, charges or expenses (including fees,
                disbursements and other charges of legal counsel) reasonably
                incurred by such party in connection with any investigation or
                proceeding. No person guilty of fraudulent misrepresentation
                (within the meaning of Section 11(f) of the Securities Act)
                shall be entitled to contribution from any person.

     e.   ADDITIONAL OBLIGATIONS OF SPSS. With respect to any registration
hereunder, SPSS shall:

          (i)   furnish to Buyer such numbers of copies of a prospectus,
                including a preliminary prospectus, in conformity with the
                requirements of the 1933 Act, and such other documents as Buyer
                may reasonably request in order to facilitate the disposition by
                Buyer of any portion of the Shares, if any;

          (ii)  use reasonable efforts to qualify the securities covered by any
                Registration Statement filed by SPSS pursuant to the terms of
                this Agreement under such other securities or Blue Sky laws of
                such jurisdictions as shall be reasonably appropriate for the
                distribution of the securities covered by the registration
                statement;

          (iii) to the extent required by NASDAQ requirements, notify NASDAQ of
                the issuance of the Shares of SPSS; and

          (iv)  notify Buyer as promptly as possible, at any time when a
                prospectus relating to the resale of any portion of the Shares
                is required to be delivered under the 1933 Act, of the happening
                of any event of which SPSS has knowledge as a result of which
                the prospectus contained in such Registration Statement, as then
                in effect, includes an untrue statement of a


                                       15
<PAGE>

                material fact or omits to state a material fact required to be
                stated therein or necessary to make the statements therein not
                misleading in light of the circumstances then existing.

     5.   REPORTS UNDER THE EXCHANGE ACT. With a view to making available to
Buyer the benefits of Rule 144 promulgated under the 1933 Act and any other rule
or regulation of the Commission that may at any time permit Buyer to sell
securities of SPSS to the public without registration, SPSS agrees to use its
reasonable efforts to (a) make and keep public information available, as those
terms are understood and defined in Rule 144, at all times; (b) file with the
Commission in a timely manner all reports and other documents required of SPSS
under the 1933 Act and the Exchange Act; and (c) furnish to Buyer forthwith upon
request a written statement by SPSS that it has complied with the reporting
requirements of the Exchange Act, a copy of the most recent annual or quarterly
report of SPSS, and such other reports and documents so filed by SPSS as may be
reasonably requested in availing Buyer of any rule or regulation of the
Commission permitting the sale of any securities of SPSS held by Buyer without
registration.

     6.   CONDITIONS PRECEDENT.

     a.   CONDITIONS TO BUYER'S OBLIGATION. The obligation of Buyer to acquire
the Shares on the Effective Date and on the date of any Subsequent Share
Issuance, as the case may be, is subject to the following conditions:

          (i)   REPRESENTATIONS AND WARRANTIES. Each of the representations and
                warranties of SPSS set forth in Section 3 hereof shall be true,
                accurate and correct in all material respects on and as of the
                Effective Date, and shall be true, accurate and correct in all
                material respects on and as of each Subsequent Share Issuance,
                in each case with the same effect as though such representations
                and warranties had been made as of the Effective Date and on the
                date of each Subsequent Share Issuance.

          (ii)  PERFORMANCE. SPSS shall have performed and complied with all
                agreements, obligations, and conditions contained in this
                Agreement and in the Research Services Agreement that are
                required to be performed or complied with by it on or before the
                Effective Date or the date of any applicable Subsequent Share
                Issuance, as the case may be.

          (iii) OPINION OF COUNSEL. SPSS shall have delivered to Buyer an
                opinion of counsel, in form and substance reasonably
                satisfactory to Buyer, with regard to the Shares, in the form
                attached hereto as Exhibit B.

     b.   CONDITIONS TO SPSS'S OBLIGATION. The obligation of SPSS to issue the
Shares to Buyer on the Effective Date and/or the date of any Subsequent Share
Issuance, as applicable, is subject to the following conditions:

          (i)   REPRESENTATIONS AND WARRANTIES. The representations and
                warranties of Buyer set forth in Section 2 hereof shall be true,
                accurate and correct on and as of the Effective Date and/or the
                date of any Subsequent Share


                                       16
<PAGE>

                Issuance, as applicable, with the same effect as though such
                representations and warranties had been made as of the Effective
                Date and/or the date of any Subsequent Share Issuance, as
                applicable.

          (ii)  SECURITIES LAW QUALIFICATION. The offer and sale to Buyer of the
                Shares shall be qualified or exempt from qualification under all
                applicable federal and state securities laws.

          (iii) PERFORMANCE. Buyer shall have performed and complied with all
                agreements, obligations and conditions contained in this
                Agreement and in the Research Services Agreement that are
                required to be performed or complied with by it on or before the
                Effective Date or the date of any applicable Subsequent Share
                Issuance, as the case may be.

     7.   EFFECTIVE DATE AND SUBSEQUENT ISSUANCE DATE DELIVERIES.

     a.   DELIVERIES OF SPSS. Buyer shall have received prior to or on the
Effective Date and/or the date of each Subsequent Share Issuance, as applicable,
all of the following documents, each in form and substance reasonably
satisfactory to Buyer and its counsel:

          (i)   A certificate of the Chief Executive Officer and the Chief
                Financial Officer of SPSS stating:

                (A)   with respect to the Effective Date, that the
                      representations and warranties of SPSS set forth in
                      Section 3 hereof are true, accurate and correct in all
                      material respects on and as of the Effective Date.

                (B)   with respect to the date of each Subsequent Share
                      Issuance, that the representations and warranties of SPSS
                      set forth in Section 3 hereof are true, accurate and
                      correct in all material respects on and as of the date of
                      such applicable Subsequent Share Issuance.

                (C)   with respect to the Effective Date and the date of each
                      Subsequent Share Issuance, that all agreements,
                      obligations and conditions contained in this Agreement
                      required to be performed and complied with by SPSS prior
                      to or on the Effective Date or the date of such applicable
                      Subsequent Share Issuance, as the case may be, have been
                      performed or compiled with.

                (D)   Written confirmation that the Initial Shares to be issued
                      on the Effective Date have been issued and delivered by
                      SPSS's transfer agent in accordance with the instructions
                      provided by Buyer in order to enable SPSS to properly
                      effect such issuance and delivery. Written confirmation
                      that the Subsequent Shares to be issued on the applicable
                      date of any Subsequent Share Issuance have been issued and
                      delivered by SPSS's transfer agent in accordance with the
                      instructions provided by Buyer in order to enable SPSS to
                      effect properly such issuance and delivery.


                                       17
<PAGE>

     b.   DELIVERIES OF BUYER. SPSS shall have received prior to or on the
Effective Date and/or the date of each Subsequent Share Issuance, as applicable,
a certificate of an authorized officer of Buyer stating that (A) with respect to
the Effective Date, that the representations and warranties of Buyer set forth
in Section 2 hereof are true, accurate and correct on and as of the Effective
Date, and (B) with respect to the date of each Subsequent Share Issuance, that
the representations and warranties of Buyer set forth in Section 2 hereof are
true, accurate and correct on and as of the date of such applicable Subsequent
Share Issuance.

     8.   MISCELLANEOUS.

     a.   NO WAIVER; CUMULATIVE REMEDIES. No failure or delay on the part of any
party to this Agreement in exercising any right, power or remedy hereunder shall
operate as a waiver thereof; nor shall any single or partial exercise of any
such right, power or remedy preclude any other or further exercise thereof or
the exercise of any other right, power or remedy hereunder. The remedies herein
provided are cumulative and not exclusive of any remedies provided by law.

     b.   AMENDMENTS, WAIVERS AND CONSENTS. This Agreement may be amended only
by an instrument in writing signed by the party to be charged with enforcement.
Any waiver or consent may be given subject to satisfaction of conditions stated
therein and any waiver or consent shall be effective only in the specific
instance and for the specific purpose for which given.

     c.   BINDING EFFECT; ASSIGNMENT. This Agreement shall be binding upon and
inure to the benefit of SPSS and Buyer and their respective heirs, successors
and assigns

     d.   SURVIVAL OF REPRESENTATIONS AND WARRANTIES. All representations and
warranties made in this Agreement or any other instrument or document delivered
in connection herewith, shall survive the execution and delivery hereof or
thereof and shall terminate one year after the date of the last Subsequent Share
Issuance.

     e.   PRIOR AGREEMENTS. This Agreement and any related documents constitute
the entire agreement between the parties hereto pertaining to the subject matter
hereof, and any and all other written or oral agreements relating to the subject
matter hereof existing between the parties hereto are expressly canceled.

     f.   SEVERABILITY. If any provision of this Agreement shall be invalid or
unenforceable in any jurisdiction, such invalidity or unenforceability shall not
affect the validity or enforceability of the remainder of this Agreement or the
validity or enforceability of this the Agreement in any other jurisdiction.

     g.   GOVERNING LAW. This Agreement shall be governed by, and construed in
accordance with the internal laws of the State of Illinois, without giving
effect to its conflict of laws principles.

     h.   HEADINGS. Article, section and subsection headings in this Agreement
are included herein for convenience of reference only and shall not constitute a
part of this Agreement for any other purpose.


                                       18
<PAGE>

     i.   COUNTERPARTS. This Agreement may be executed in any number of
counterparts, all of which taken together shall constitute one and the same
instrument, and any of the parties hereto may execute this Agreement by signing
any such counterpart.

     j.   FURTHER ASSURANCES. From and after the date of this Agreement, upon
the request of SPSS, Buyer shall execute and deliver such instruments, documents
and other writings as may be reasonably necessary or desirable to confirm and
carry out and to effectuate fully the intent and purposes of this Agreement and
the Shares.

     9.   NOTICES. Any notice required or permitted hereunder shall be given in
writing (unless otherwise specified herein) and shall be deemed effectively
given, (i) on the date delivered, (a) if by personal delivery, or (b) if advance
copy is given by fax, (ii) seven business days after deposit in the United
States Postal Service by regular or certified mail, or (iii) three business days
mailing by international express courier, with postage and fees prepaid,
addressed to each of the other parties thereunto entitled at the following
addresses, or at such other addresses as a party may designate by ten days
advance written notice to each of the other parties hereto:

          SPSS:        SPSS Inc.
                       233 South Wacker Drive
                       Chicago, Illinois  60606
                       Attention: Jack Noonan President and
                         Chief Executive Officer
                       Facsimile: 312-651-3558

                       with a copy to:

                       Lawrence R. Samuels, Esq.
                       Ross & Hardies
                       150 North Michigan Avenue
                       Suite 2500
                       Chicago, Illinois  60601
                       Facsimile: 312-750-8600

          BUYER:       America Online, Inc.
                       22000 AOL Way
                       Dulles, Virginia 20166
                       Attention: David M. Colburn, President, Business
                         Affairs and Development
                       Facsimile: 703-265-1202

                       with a copy to:

                       America Online, Inc.
                       22000 AOL Way
                       Dulles, Virginia 20166
                       Attention: General Counsel
                       Facsimile: 703-265-2208



                                       19
<PAGE>

     IN WITNESS WHEREOF, this Agreement has been duly executed by the parties
hereto as of the date set forth below.


BUYER:


America Online, Inc., a Delaware corporation


By:  /s/ Lynda M. Clarizio
   ----------------------------------------
     Name:  Lynda M. Clarizio
     Title: Senior Vice President


SPSS:

SPSS INC., a Delaware corporation



By:  /s/ Jack Noonan
   ----------------------------------------
     Jack Noonan
     President and Chief Executive Officer






                                       20