EXHIBIT 3.1

                          AMENDED AND RESTATED BY-LAWS

                                       OF

                                    SPSS INC.

             (Incorporated under the Laws of the State of Delaware)

                                    ARTICLE I

                               OFFICES AND RECORDS

     SECTION (1) Registered Office. The registered office of the Corporation
shall be established and maintained at the office of The Corporation Trust
Company, at 1209 Orange Street in the City of Wilmington, County of New Castle,
State of Delaware, and The Corporation Trust Company shall be the registered
agent of the Corporation at such address.

     SECTION (2) Other Offices. The Corporation may have such other offices,
either within or without the State of Delaware, as the Board of Directors may
designate or as the business of the Corporation may from time to time require.

     SECTION (3) Book and Records. The books and records of the Corporation may
be kept outside the State of Delaware at such place or places as may from time
to time be designated by the Board of Directors.

                                   ARTICLE II

                                  STOCKHOLDERS

     SECTION (1) Annual Meeting. Annual meetings of stockholders for the
election of directors, and for such other business as may be stated in the
notice of the meeting, shall be held at such place, either within or without the
State of Delaware, and at such time and date as the Board of Directors, by
resolution, shall determine and as set forth in the notice of the meeting. At
each annual meeting, the stockholders entitled to vote shall elect a Board of
Directors, or class thereof, and they may transact such other corporate business
as shall be stated in the notice of the meeting.

     SECTION (2) Special Meeting. Special meetings of the stockholders may be
held at such time and place, within or without the State of Delaware, as shall
be stated in the notice of the meeting, and may be called only by the Chairman
of the Board or by a vote of a majority of the total number of directors which
the Corporation would have if there were no vacancies (the "Whole Board").

     SECTION (3) Notice of Meeting. Written or printed notice, stating the
place, day and hour of the meeting and the purpose or purposes for which the
meeting is called, shall be delivered by the Corporation not less than ten (10)
days nor more than sixty (60) days before the date of the meeting, either
personally or by mail, to each stockholder of record entitled to vote at



such meeting. If mailed, such notice shall be deemed to be delivered when
deposited in the United States mail with postage thereon prepaid, addressed to
the stockholder at his address as it appears on the stock transfer books of the
Corporation. Such further notice shall be given as may be required by law. Only
such business shall be conducted at a special meeting of stockholders as shall
have been brought before the meeting pursuant to the Corporation's notice of
meeting.

     SECTION (4) Quorum and Adjournment. Except as otherwise provided by law or
by the Certificate of Incorporation, the holders of a majority of the
outstanding shares of capital stock of the Corporation entitled to vote
generally in the election of directors (the "Voting Stock"), represented in
person or by proxy, shall constitute a quorum at a meeting of stockholders. The
Chairman of the meeting or a majority of the shares so represented may adjourn
the meeting from time to time, whether or not there is such a quorum. No notice
of the time and place of adjourned meetings need be given except as required by
law. The stockholders present at a duly called meeting at which a quorum is
present may continue to transact business until adjournment, notwithstanding the
withdrawal of enough stockholders to leave less than a quorum.

     SECTION (5) Voting. Each stockholder shall be entitled to vote in
accordance with the terms of the Certificate of Incorporation and in accordance
with the provisions of these By-Laws, in person or by proxy, but no proxy shall
be voted after three years from its date, unless such proxy provides for a
longer period. A duly executed proxy shall be irrevocable if it states that it
is irrevocable and if, and only as long as, it is coupled with an interest
legally sufficient to support an irrevocable power. A stockholder may revoke any
proxy which is not irrevocable by attending the meeting and voting in person or
by filing with the person recording the proceedings of the meeting an instrument
in writing revoking the proxy or another duly executed proxy bearing a later
date.

     A complete list of the stockholders entitled to vote at the ensuing
election, arranged in alphabetical order, with the address of each, and the
number of shares held by each, shall be open to the examination of any
stockholder, for any purpose germane to the meeting, during ordinary business
hours for a period of at least ten (10) days prior to the meeting, either at a
place within the city where the meeting is to be held, which place shall be
specified in the notice of the meeting, or, if not so specified, at the place
where the meeting is to be held. The list shall also be produced and kept at the
time and place of the meeting during the whole time thereof, and may be
inspected by any stockholder who is present.

     SECTION (6) Notice of Stockholder Business and Nominations.

          1. Annual Meetings of Stockholders. Nominations of persons for
election to the Board of Directors of the Corporation and the proposal of
business to be considered by the stockholders may be made at an annual meeting
of stockholders (a) pursuant to the Corporation's notice of meeting, (b) by or
at the direction of the Board of Directors or (c) by any stockholder of the
Corporation who was a stockholder of record at the time of giving of notice
provided for in this By-Law, who is entitled to vote at the meeting and who
complies with the notice procedures set forth in this By-Law.

               a. For nominations or other business to be properly brought
before an annual meeting by a stockholder pursuant to clause (c) of paragraph
(1) above, the stockholder


                                       2



must have given timely notice thereof in writing to the Secretary of the
Corporation and such other business must otherwise be a proper matter for
stockholder action. To be timely, a stockholder's notice shall be delivered to
the Secretary at the principal executive offices of the Corporation not later
than the close of business on the 60th day nor earlier than the close of
business on the 90th day prior to the first anniversary of the preceding year's
annual meeting; provided, however, that in the event that the date of the annual
meeting is more than 30 days before or more than 60 days after such anniversary
date, notice by the stockholder to be timely must be so delivered not earlier
than the close of business on the 90th day prior to such annual meeting and not
later than the close of business on the later of the 60th day prior to such
annual meeting or the 10th day following the day on which public announcement of
the date of such meeting is first made by the Corporation. In no event shall the
public announcement of an adjournment of an annual meeting commence a new time
period for the giving of a stockholder's notice as described above. Such
stockholder's notice shall set forth (a) as to each person whom the stockholder
proposes to nominate for election or reelection as a director all information
relating to such person that is required to be disclosed in solicitations of
proxies for election of directors, or is otherwise required, in each case
pursuant to Regulation 14A under the Securities Exchange Act of 1934, as amended
(the "Exchange Act") (including such person's written consent to being named in
the proxy statement as a nominee and to serving as a director if elected); (b)
as to any other business that the stockholder proposes to bring before the
meeting, a brief description of the business desired to be brought before the
meeting, the reasons for conducting such business at the meeting and any
material interest in such business of such stockholder and the beneficial owner,
if any, on whose behalf the proposal is made; and (c) as to the stockholder
giving the notice and the beneficial owner, if any, on whose behalf the
nomination or proposal is made (i) the name and address of such stockholder, as
they appear on the Corporation's books, and of such beneficial owner and (ii)
the class and number of shares of the Corporation which are owned beneficially
and of record by such stockholder and such beneficial owner.

               b. Notwithstanding anything in these By-Laws to the contrary, in
the event that the number of directors to be elected to the Board of Directors
of the Corporation is increased and there is no public announcement by the
Corporation naming all of the nominees for director or specifying the size of
the increased Board of Directors at least 70 days prior to the first anniversary
of the preceding year's annual meeting, a stockholder's notice required by this
By-Law shall also be considered timely, but only with respect to nominees for
any new positions created by such increase, if it shall be delivered to the
Secretary at the principal executive offices of the Corporation not later than
the close of business on the 10th day following the day on which such public
announcement is first made by the Corporation.

          2. Special Meetings of Stockholders. Only such business shall be
conducted at a special meeting of stockholders as shall have been brought before
the meeting pursuant to the Corporation's notice of meeting. Nominations of
persons for election to the Board of Directors may be made at a special meeting
of stockholders at which directors are to be elected pursuant to the
Corporation's notice of meeting (a) by or at the direction of the Board of
Directors or (b) provided that the Board of Directors has determined that
directors shall be elected at such meeting, by any stockholder of the
Corporation who is a stockholder of record at the time of giving of notice
provided for in this By-Law, who shall be entitled to vote at the meeting and
who complies with the notice procedures set forth in this By-Law. In the event
the


                                       3



Corporation calls a special meeting of stockholders for the purpose of electing
one or more directors to the Board of Directors, any such stockholder may
nominate a person or persons (as the case may be), for election to such
position(s) as specified in the Corporation's notice of meeting, if the
stockholder's notice required by these By-Laws shall be delivered to the
Secretary at the principal executive offices of the Corporation not earlier than
the close of business on the 90th day prior to such special meeting and not
later than the close of business on the later of the 60th day prior to such
special meeting or the 10th day following the day on which public announcement
is first made of the date of the special meeting and of the nominees proposed by
the Board of Directors to be elected at such meeting. In no event shall the
public announcement of an adjournment of a special meeting commence a new time
period for the giving of a stockholder's notice as described above.

          3. General. (1) Only such persons who are nominated in accordance with
the procedures set forth in this By-Law shall be eligible to serve as directors
and only such business shall be conducted at a meeting of stockholders as shall
have been brought before the meeting in accordance with the procedures set forth
in this By-Law. Except as otherwise provided by law, the Certificate of
Incorporation or these By-Laws, the Chairman of the meeting shall have the power
and duty to determine whether a nomination or any business proposed to be
brought before the meeting was made or proposed, as the case may be, in
accordance with the procedures set forth in this By-Law and, if any proposed
nomination or business is not in compliance with this By-Law, to declare that
such defective proposal or nomination shall be disregarded.

               (2) For purposes of this By-Law, "public announcement" shall mean
disclosure in a press release reported by the Dow Jones News Service, Associated
Press or comparable national news service or in a document publicly filed by the
Corporation with the Securities and Exchange Commission pursuant to Section 13,
14 or 15(d) of the Exchange Act.

               (3) Notwithstanding the foregoing provisions of this By-Law, a
stockholder shall also comply with all applicable requirements of the Exchange
Act and the rules and regulations thereunder with respect to the matters set
forth in this By-Law. Nothing in this By-Law shall be deemed to affect any
rights of stockholders to request inclusion of proposals in the Corporation's
proxy statement pursuant to Rule 14a-8 under the Exchange Act.

     SECTION (7) Procedure for Election of Directors; Required Vote. Election of
directors at all meetings of the stockholders at which directors are to be
elected shall be by ballot, and, a plurality of the votes cast thereat shall
elect directors. Except as otherwise provided by law, the Certificate of
Incorporation, or these By-Laws, in all matters other than the election or
removal of directors, the affirmative vote of a majority of the shares present
in person or represented by proxy at the meeting and entitled to vote on the
matter shall be the act of the stockholders.

     SECTION (8) Inspectors of Elections; Opening and Closing the Polls. The
Board of Directors by resolution may appoint one or more inspectors, which
inspector or inspectors may include individuals who serve the Corporation in
other capacities, including, without limitation, as officers, employees, agents
or representatives, to act at the meetings of stockholders and make a written
report thereof. One or more persons may be designated as alternate inspectors to
replace any inspector who fails to act. If no inspector or alternate has been
appointed to act or is


                                       4



able to act at a meeting of stockholders, the Chairman of the meeting may
appoint one or more inspectors to act at the meeting. Each inspector, before
discharging his or her duties, shall take and sign an oath faithfully to execute
the duties of inspector with strict impartiality and according to the best of
his or her ability. The inspectors shall have the duties prescribed by law.

     The Chairman of the meeting shall fix and announce at the meeting the date
and time of the opening and the closing of the polls for each matter upon which
the stockholders will vote at a meeting.

     SECTION (9) No Stockholder Action by Written Consent. Any action required
or permitted to be taken by the stockholders of the Corporation must be effected
at an annual or special meeting of stockholders of the Corporation and may not
be effected by any consent in writing by such stockholders.

                                  ARTICLE III

                               BOARD OF DIRECTORS

     SECTION (1) General Powers. The business and affairs of the Corporation
shall be managed under the direction of the Board of Directors. In addition to
the powers and authorities by these By-Laws expressly conferred upon them, the
Board of Directors may exercise all such powers of the Corporation and do all
such lawful acts and things as are not by statute or by the Certificate of
Incorporation or by these By-Laws required to be exercised or done by the
stockholders.

     SECTION (2) Number, Tenure and Qualifications. The number of directors
shall be fixed from time to time exclusively pursuant to a resolution adopted by
a majority of the Whole Board, but shall consist of not more than nine (9) nor
less than five (5) directors. Commencing with the date the Corporation's
Certificate of Incorporation is accepted for filing by the Delaware Secretary of
State's Office in connection with the Corporation's initial public offering, the
directors shall be divided, with respect to the time for which they severally
hold office, into three classes, as nearly equal in number as is reasonably
possible, with the term of office of the first class to expire at the 1994
annual meeting of stockholders, the term of office of the second class to expire
at the 1995 annual meeting of stockholders and the term of office of the third
class to expire at the 1996 annual meeting of stockholders, with each director
to hold office until his or her successor shall have been duly elected and
qualified. At each annual meeting of stockholders, commencing with the 1994
annual meeting, directors elected to succeed those directors whose terms then
expire shall be elected for a term of office to expire at the third succeeding
annual meeting of stockholders after their election, with each director to hold
office until his or her successor shall have been duly elected and qualified.

     SECTION (3) Regular Meetings. A regular meeting of the Board of Directors
shall be held without other notice than as provided by this By-Law immediately
after, and at the same place as, the Annual Meeting of Stockholders. The Board
of Directors may, by resolution, provide the time and place for the holding of
different or additional regular meetings without other notice than such
resolution.


                                       5



     SECTION (4) Special Meetings. Special meetings of the Board of Directors
shall be called at the request of the Chairman of the Board, the President or a
majority of the Board of Directors then in office. The person or persons
authorized to call special meetings of the Board of Directors may fix the place
and time of the meetings.

     SECTION (5) Notice. Notice of any special meeting of directors shall be
given to each director at his business or residence in writing by hand delivery,
first-class or overnight mail or courier service, telegram or facsimile
transmission, or orally by telephone. If mailed by first-class mail, such notice
shall be deemed adequately delivered when deposited in the United States mails
so addressed, with postage thereon prepaid, at least five (5) days before such
meeting. If by telegram, overnight mail or courier service, such notice shall be
deemed adequately delivered when the telegram is delivered to the telegraph
company or the notice is delivered to the overnight mail or courier service
company at least twenty-four (24) hours before such meeting. If by facsimile
transmission, such notice shall be deemed adequately delivered when the notice
is transmitted at least twelve (12) hours before such meeting. If by telephone
or by hand delivery, the notice shall be given at least twelve (12) hours prior
to the time set for the meeting. Neither the business to be transacted at, nor
the purpose of, any regular or special meeting of the Board of Directors need be
specified in the notice of such meeting, except for amendments to these By-Laws,
as provided under Article VIII. A meeting may be held at any time without notice
if all the directors are present or if those not present waive notice of the
meeting in accordance with Article VI, Section 4 of these By-Laws.

     SECTION (6) Action by Consent of Board of Directors. Any action required or
permitted to be taken at any meeting of the Board of Directors or of any
committee thereof may be taken without a meeting if all members of the Board or
committee, as the case may be, consent thereto in writing, and the writing or
writings are filed with the minutes of proceedings of the Board or committee.

     SECTION (7) Conference Telephone Meetings. Members of the Board of
Directors, or any committee thereof, may participate in a meeting of the Board
of Directors or such committee by means of conference telephone or similar
communications equipment by means of which all persons participating in the
meting can hear each other, and such participation in a meeting shall constitute
presence in person at such meeting.

     SECTION (8) Quorum. Subject to Article III, Section 9, a whole number of
directors equal to at least a majority of the Whole Board shall constitute a
quorum for the transaction of business, but if at any meeting of the Board of
Directors there shall be less than a quorum present, a majority of the directors
present may adjourn the meeting from time to time without further notice. The
act of the majority of the directors present at a meeting at which a quorum is
present shall be the act of the Board of Directors. The directors present at a
duly organized meeting may continue to transact business until adjournment,
notwithstanding the withdrawal of enough directors to leave less than a quorum.

     SECTION (9) Vacancies. Unless the Board of Directors otherwise determines,
vacancies resulting from death, resignation, retirement, disqualification,
removal from office or other cause, and newly created directorships resulting
from any increase in the authorized number of directors, may be filled only by
the affirmative vote of a majority of the remaining directors,


                                       6



though less than a quorum of the Board of Directors, and directors so chosen
shall hold office for a term expiring at the annual meeting of stockholders at
which the term of office of the class to which they have been elected expires
and until such director's successor shall have been duly elected and qualified.
No decrease in the number of authorized directors constituting the Whole Board
shall shorten the term of any incumbent director.

     SECTION (10) Executive and Other Committees. The Board of Directors may, by
resolution adopted by a majority of the Whole Board, designate an Executive
Committee to exercise, subject to applicable provisions of law, all the powers
of the Board in the management of the business and affairs of the Corporation
when the Board is not in session, including without limitation the power to
declare dividends, to authorize the issuance of the Corporation's capital stock
and to adopt a certificate of ownership and merger pursuant to Section 253 of
the General Corporation Law of the State of Delaware, and may, by resolution
similarly adopted, designate one or more other committees. The Executive
Committee and each such other committee shall consist of two or more directors
of the Corporation. The Board may designate one or more directors as alternate
members of any committee, who may replace any absent or disqualified member at
any meeting of the committee. Any such committee, other than the Executive
Committee (the powers of which are expressly provided for herein), may to the
extent permitted by law exercise such powers and shall have such
responsibilities as shall be specified in the designating resolution. In the
absence or disqualification of any member of such committee or committees, the
member or members thereof present at any meeting and not disqualified from
voting, whether or not constituting a quorum, may unanimously appoint another
member of the Board to act at the meeting in the place of any such absent or
disqualified member. Each committee shall keep written minutes of its
proceedings and shall report such proceedings to the Board when required.

     A majority of any committee may determine its action and fix the time and
place of its meetings, unless the Board shall otherwise provide. Notice of such
meetings shall be given to each member of the committee in the manner provided
for in Article III, Section 5 of these By-Laws. The Board shall have power at
any time to fill vacancies in, to change the membership of, or to dissolve any
such committee. Nothing herein shall be deemed to prevent the Board from
appointing one or more committees consisting in whole or in part of persons who
are not directors of the Corporation; provided, however, that no such committee
shall have or may exercise any authority of the Board.

     SECTION (11) Removal. Any director, or the entire Board of Directors, may
be removed from office at any time, but only for cause and only by the
affirmative vote of the holders of at least 80 percent of the voting power of
all of the then-outstanding shares of Voting Stock, voting together as a single
class.

     SECTION (12) Records. The Board of Directors shall cause to be kept a
record containing the minutes of the proceedings of the meetings of the Board
and of the stockholders, appropriate stock books and registers and such books of
records and accounts as may be necessary for the proper conduct of the business
of the Corporation.

     SECTION (13) Compensation. Directors shall not receive any stated salary
for their services as directors or as members of committees, but by resolution
of the board a fixed fee


                                       7



and expenses of attendance may be allowed for attendance at each meeting.
Nothing herein contained shall be construed to preclude any director from
serving the Corporation in any other capacity as an officer, agent or otherwise,
and receiving compensation therefor.

                                   ARTICLE IV

                                    OFFICERS

     SECTION (1) Elected Officers. The elected officers of the Corporation shall
be a Chairman of the Board of Directors, a President, a Secretary, a Treasurer,
and such other officers (including, without limitation, a Controller and a Chief
Financial Officer) as the Board of Directors from time to time may deem proper.
The Chairman of the Board shall be chosen from among the directors. All officers
elected by the Board of Directors shall each have such powers and duties as
generally pertain to their respective offices, subject to the specific
provisions of this Article IV. Such officers shall also have such powers and
duties as from time to time may be conferred by the Board of Directors or by any
committee thereof. The Board or any committee thereof may from time to time
elect, or the Chairman of the Board or President may appoint, such other
officers (including one or more Vice Presidents, Assistant Secretaries,
Assistant Treasurers, and Assistant Controllers) and such agents, as may be
necessary or desirable for the conduct of the business of the Corporation. Such
other officers and agents shall have such duties and shall hold their offices
for such terms as shall be provided in these By-Laws or as may be prescribed by
the Board or such committee or by the Chairman of the Board or President, as the
case may be.

     SECTION (2) Election and Term of Office. The elected officers of the
Corporation shall be elected annually by the Board of Directors at the regular
meeting of the Board of Directors held after the annual meeting of the
stockholders. If the election of officers shall not be held at such meeting,
such election shall be held as soon thereafter as convenient. Each officer shall
hold office until his successor shall have been duly elected and shall have
qualified or until his death or until he shall resign, but any officer (other
than the Chairman of the Board or President) may be removed from office at any
time by either the affirmative vote of a majority of the Whole Board or by the
Chairman of the Board or President. The Chairman of the Board and the President
may only be removed from office by the affirmative vote of a majority of the
Whole Board. Such removal shall be without prejudice to the contractual rights,
if any, of the person so removed.

     SECTION (3) Chairman of the Board. The Chairman of the Board shall preside
at all meetings of the stockholders and of the Board of Directors. The Chairman
of the Board shall be responsible for the general management of the affairs of
the Corporation and shall perform all duties incidental to his office which may
be required by law and all such other duties as are properly required of him by
the Board of Directors. He shall make reports to the Board of Directors and the
stockholders, and shall see that all orders and resolutions of the Board of
Directors and of any committee thereof are carried into effect. The Chairman of
the Board may also serve as President, if so elected by the Board.

     SECTION (4) President. The President shall act in a general executive
capacity and shall assist the Chairman of the Board in the administration and
operation of the Corporation's


                                       8



business and general supervision of its policies and affairs. The President
shall, in the absence of or because of the inability to act of the Chairman of
the Board, perform all duties of the Chairman of the Board and preside at all
meetings of stockholders and of the Board of Directors.

     SECTION (5) Vice Presidents. Each Vice President shall have such powers and
shall perform such duties as shall be assigned to him by the Board of Directors,
the Chairman of the Board or the President.

     SECTION (6) Chief Financial Officer. The Chief Financial Officer (if any)
shall be a Vice President and act in an executive financial capacity. He shall
assist the Chairman of the Board and the President in the general supervision of
the Corporation's financial policies and affairs.

     SECTION (7) Treasurer. The Treasurer shall exercise general supervision
over the receipt, custody and disbursement of corporate funds. The Treasurer
shall cause the funds of the Corporation to be deposited in such banks as may be
authorized by the Board of Directors, or in such banks as may be designated as
depositaries in the manner provided by resolution of the Board of Directors. He
shall have such further powers and duties and shall be subject to such
directions as may be granted or imposed upon him from time to time by the Board
of Directors, the Chairman of the Board or the President.

     SECTION (8) Secretary. The Secretary shall keep or cause to be kept in one
or more books provided for that purpose, the minutes of all meetings of the
Board, the committees of the Board and the stockholders; he shall see that all
notices are duly given in accordance with the provisions of these By-Laws and as
required by law; he shall be custodian of the records and the seal of the
Corporation and affix and attest the seal to all stock certificates of the
Corporation (unless the seal of the Corporation on such certificates shall be a
facsimile, as hereinafter provided) and affix and attest the seal to all other
documents to be executed on behalf of the Corporation under its seal; and he
shall see that the books, reports, statements, certificates and other documents
and records required by law to be kept and filed are properly kept and filed;
and in general, he shall perform all the duties incident to the office of
Secretary and such other duties as from time to time may be assigned to him by
the Board, the Chairman of the Board or the President.

     SECTION (9) Removal. Any officer elected, or agent appointed, by the Board
of Directors may be removed by the affirmative vote of a majority of the Whole
Board whenever, in their judgment, the best interests of the Corporation would
be served thereby. Any officer or agent appointed by the Chairman of the Board
or the President may be removed by him whenever, in his judgment, the best
interests of the Corporation would be served thereby. No elected officer shall
have any contractual rights against the Corporation for compensation by virtue
of such election beyond the date of the election of his successor, his death,
his resignation or his removal, whichever event shall first occur, except as
otherwise provided in an employment contract or under an employee deferred
compensation plan.

     SECTION (10) Vacancies. A newly created elected office and a vacancy in any
elected office because of death, resignation, or removal may be filled by the
Board of Directors for the unexpired portion of the term at any meeting of the
Board of Directors. Any vacancy in


                                       9



an office appointed by the Chairman of the Board or the President because of
death, resignation, or removal may be filled by the Chairman of the Board or the
President.

                                    ARTICLE V

                  STOCK CERTIFICATE, TRANSFERS AND RECORD DATE

     SECTION (1) Stock Certificates and Transfers. The interest of each
stockholder of the Corporation shall be evidenced by certificates for shares of
stock in such form as the appropriate officers of the Corporation may from time
to time prescribe; provided that the Board of Directors may provide by
resolution or resolutions that some or all shares of stock in the Corporation
shall be uncertificated shares. Any such resolution shall not apply to shares
evidenced by a certificate until such certificate is surrendered to the
Corporation. Any certificates for shares of stock shall be signed, countersigned
and registered in such manner as the Board of Directors may by resolution
prescribe, which resolution may permit all or any of the signatures on such
certificates to be in facsimile. In case any officer, transfer agent or
registrar who has signed or whose facsimile signature has been placed upon a
certificate has ceased to be such officer, transfer agent or registrar before
such certificate is issued, it may be issued by the Corporation with the same
effect as if such person were such officer, transfer agent or registrar at the
date of issue.

     SECTION (2) Lost, Stolen or Destroyed Certificates. No certificate for
shares of stock in the Corporation, or uncertificated shares, shall be issued in
place of any certificate alleged to have been lost, destroyed or stolen, except
on production of such evidence of such loss, destruction or theft and on
delivery to the Corporation of a bond of indemnity in such amount, upon such
terms and secured by such surety, as the Board of Directors or any financial
officer may in its or his discretion require.

     SECTION (3) Transfer of Shares. The shares of stock of the Corporation
shall be transferable only upon its books by the holders thereof in person or by
their duly authorized attorneys or legal representatives, and, upon the transfer
of any shares of stock evidenced by certificates, the old certificates shall be
surrendered to the Corporation by the delivery thereof to the person in charge
of the stock and transfer books and ledgers, or to such other person as the
directors may designate, by whom they shall be cancelled. A record shall be made
of each transfer and whenever a transfer shall be made for collateral security,
and not absolutely, it shall be so expressed in the entry of the transfer.

     SECTION (4) Stockholders Record Date. In order that the Corporation may
determine the stockholders entitled to notice of or to vote at any meeting of
stockholders or any adjournment thereof, or to express consent to corporate
action in writing without a meeting (if permitted), or entitled to receive
payment of any dividend or other distribution or allotment of any rights, or
entitled to exercise any rights in respect of any change, conversion or exchange
of stock or for the purpose of any other lawful action, the Board of Directors
may fix, in advance, a record date, which shall not be more than 60 nor less
than ten days before the date of such meeting, nor more than 60 days prior to
any other action. A determination of stockholders of record entitled to notice
of or to vote at a meeting of stockholders shall apply to any adjournment of the
meeting; provided, however, that the Board of Directors may fix a new record
date for the adjourned meeting.


                                       10



                                   ARTICLE VI

                            MISCELLANEOUS PROVISIONS

     SECTION (1) Fiscal Year. The fiscal year of the Corporation shall begin on
the first day of January and end on the thirty-first day of December of each
year.

     SECTION (2) Dividends. The Board of Directors may from time to time
declare, and the Corporation may pay, dividends on its outstanding shares in the
manner and upon the terms and conditions provided by law and the Certificate of
Incorporation.

     SECTION (3) Seal. The corporate seal shall have inscribed thereon the words
"Corporate Seal", and around the margin thereof the words "SPSS Inc. Delaware."

     SECTION (4) Waiver of Notice. Whenever any notice is required to be given
to any stockholder or director of the Corporation under the provisions of the
General Corporation Law of the State of Delaware or these By-Laws, a waiver
thereof in writing, signed by the person or persons entitled to such notice,
whether before or after the time stated therein, shall be deemed equivalent to
the giving of such notice. Neither the business to be transacted at, nor the
purpose of, any annual or special meeting of the stockholders or the Board of
Directors or committee thereof need be specified in any waiver of notice of such
meeting.

     SECTION (5) Audits. The accounts, books and records of the Corporation
shall be audited upon the conclusion of each fiscal year by an independent
certificated public accountant selected by the Board of Directors, and it shall
be the duty of the Board of Directors to cause such audit to be done annually.

     SECTION (6) Resignations. Any director or any officer, whether elected or
appointed, may resign at any time by giving written notice of such resignation
to the Chairman of the Board, the President, or the Secretary, and such
resignation shall be deemed to be effective as of the close of business on the
date said notice is received by the Chairman of the Board, the President, or the
Secretary, or at such later time as is specified therein. No formal action shall
be required of the Board of Directors or the stockholders to make any such
resignation effective.

                                   ARTICLE VII

                            CONTRACTS, PROXIES, ETC.

     SECTION (1) Contracts. Except as otherwise required by law, the Certificate
of Incorporation or these By-Laws, any contracts or other instruments may be
executed and delivered in the name and on the behalf of the Corporation by such
officer or officers of the Corporation as the Board of Directors may from time
to time direct. Such authority may be general or confined to specific instances
as the Board may determine. The Chairman of the Board, the President or any Vice
President may execute bonds, contracts, deeds, leases and other instruments to
be made or executed for or on behalf of the Corporation. Subject to any
restrictions imposed by the Board of Directors or the Chairman of the Board, the
President or any Vice President of the Corporation may delegate contractual
powers to others under his


                                       11



jurisdiction, it being understood, however, that any such delegation of power
shall not relieve such officer of responsibility with respect to the exercise of
such delegated power.

     SECTION (2) Voting of Shares in Other Corporations. Unless otherwise
provided by resolution adopted by the Board of Directors, the Chairman of the
Board, the President or any Vice President may from time to time appoint an
attorney or attorneys or agent or agents of the Corporation, in the name and on
behalf of the Corporation, to cast the votes which the Corporation may be
entitled to cast as the holder of stock or other securities in any other
corporation, any of whose stock or other securities may be held by the
Corporation, at meetings of the holders of the stock or other securities of such
other corporation, or to consent in writing, in the name of the Corporation as
such holder, to any action by such other corporation, and may instruct the
person or persons so appointed as to the manner of casting such votes or giving
such consent, and may execute or cause to be executed in the name and on behalf
of the Corporation and under its corporate seal or otherwise, all such written
proxies or other instruments as he may deem necessary or proper in the premises.

                                  ARTICLE VIII

                                   AMENDMENTS

     These By-Laws may be altered or repealed, and any By-Laws may be made, at
any annual meeting of the stockholders or at any special meeting thereof if
notice of the proposed alteration or repeal of the By-Laws or of the By-Laws to
be made is contained in the notice of such meeting, by the affirmative vote of
the holders of at least 80% of the voting power of the then outstanding Voting
Stock, or by the affirmative vote of a majority of the total number of
directors, at any regular meeting of the Board of Directors, or at any special
meeting of the Board of Directors, if notice of the proposed alteration or
repeal, or of the By-Laws to be made, is contained in the notice of such special
meeting.


                                       12