UNITED STATES
             SECURITIES AND EXCHANGE COMMISSION
                      WASHINGTON, D.C.


                         SCHEDULE 13G


           Under the Securities Exchange Act of 1934
                     (Amendment No. 3)*

                      GARTNER GROUP, Inc.
- -----------------------------------------------------------
                    (Name of Issuer)

                   Common Stock, Class A
- -----------------------------------------------------------
               (Title of Class of Securities)

                         366651107
- -----------------------------------------------------------
                       (CUSIP Number)
Check the following  box if a fee is being paid with this  statement ( ). (A fee
is not required only if the reporting  person:  (1) has a previous  statement on
file  reporting  beneficial  ownership of more than five percent of the class of
securities  described  in Item 1;  and (2) has  filed  no  amendment  subsequent
thereto reporting beneficial ownership of five percent or less of such class.)
(See Rule 13d-7.)

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).
                    (Continued on following page(s))
                           Page 1 of 8 Pages






                       SCHEDULE 13G

CUSIP NO. 366651107
- --------------------

1. NAME OF REPORTING PERSON
   S.S. OR I.R.S. IDENTIFICATION NO. ABOVE PERSON

   Cognizant Corporation 06-1450569
- -----------------------------------------------------------

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                (a)
                                                (b)
- -----------------------------------------------------------

3. SEC USE ONLY
- -----------------------------------------------------------
4. CITIZENSHIP OR PLACE OF ORGANIZATION
   Delaware
- -----------------------------------------------------------
NUMBER OF           5. SOLE VOTING POWER
SHARES                 31,701,369
                  -----------------------------------------
BENEFICIALLY        6. SHARED VOTING POWER
OWNED BY                16,497,728
EACH              -----------------------------------------
REPORTING           7. SOLE DISPOSITIVE POWER
PERSON                 31,701,369
WITH              -----------------------------------------
                    8. SHARED DISPOSITIVE POWER
                        16,497,728
                  -----------------------------------------
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
    PERSON
    48,199,097
- -----------------------------------------------------------
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ( )
- -----------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 49.1%
- -----------------------------------------------------------
12. TYPE OF REPORTING PERSON*
    CO
- -----------------------------------------------------------
               *SEE INSTRUCTIONS BEFORE FILLING OUT!






                       SCHEDULE 13G

CUSIP NO. 366651107
- --------------------

1. NAME OF REPORTING PERSON
   S.S. OR I.R.S. IDENTIFICATION NO. ABOVE PERSON

   Cognizant Enterprises, Inc.    13-3528119
- -----------------------------------------------------------

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                (a)
                                                (b)
- -----------------------------------------------------------

3. SEC USE ONLY
- -----------------------------------------------------------
4. CITIZENSHIP OR PLACE OF ORGANIZATION
   Delaware
- -----------------------------------------------------------

NUMBER OF           5. SOLE VOTING POWER
SHARES                        -0-
                  -----------------------------------------
BENEFICIALLY        6. SHARED VOTING POWER
OWNED BY                13,257,728
EACH              -----------------------------------------
REPORTING           7. SOLE DISPOSITIVE POWER
PERSON                        -0-
WITH              -----------------------------------------
                    8. SHARED DISPOSITIVE POWER
                        13,257,728
                  -----------------------------------------
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
    PERSON
    13,257,728
- -----------------------------------------------------------
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ( )
- -----------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)13.6%
- -----------------------------------------------------------
12. TYPE OF REPORTING PERSON*
    CO
- -----------------------------------------------------------
           *SEE INSTRUCTIONS BEFORE FILLING OUT!






                       SCHEDULE 13G

CUSIP NO. 366651107
- --------------------

1. NAME OF REPORTING PERSON
   S.S. OR I.R.S. IDENTIFICATION NO. ABOVE PERSON

   Nielsen Media Research, Inc.    06-1463993
- -----------------------------------------------------------

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                (a)
                                                (b)
- -----------------------------------------------------------

3. SEC USE ONLY
- -----------------------------------------------------------
4. CITIZENSHIP OR PLACE OF ORGANIZATION
   Delaware
- -----------------------------------------------------------

NUMBER OF           5. SOLE VOTING POWER
SHARES                       -0-
                  -----------------------------------------
BENEFICIALLY        6. SHARED VOTING POWER
OWNED BY                2,512,727
EACH              -----------------------------------------
REPORTING           7. SOLE DISPOSITIVE POWER
PERSON                       -0-
WITH              -----------------------------------------
                    8. SHARED DISPOSITIVE POWER
                        2,512,727
                  -----------------------------------------
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
    PERSON
    2,512,727
- -----------------------------------------------------------
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ( )
- -----------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 2.6%
- -----------------------------------------------------------
12. TYPE OF REPORTING PERSON*
    CO
- -----------------------------------------------------------
           *SEE INSTRUCTIONS BEFORE FILLING OUT!






                       SCHEDULE 13G

CUSIP NO. 366651107
- --------------------

1. NAME OF REPORTING PERSON
   S.S. OR I.R.S. IDENTIFICATION NO. ABOVE PERSON

   Cognizant Licensing Associates, L.P.    98-0137321
- -----------------------------------------------------------

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                (a)
                                                (b)
- -----------------------------------------------------------

3. SEC USE ONLY
- -----------------------------------------------------------
4. CITIZENSHIP OR PLACE OF ORGANIZATION
   Delaware
- -----------------------------------------------------------

NUMBER OF           5. SOLE VOTING POWER
SHARES                       -0-
                  -----------------------------------------
BENEFICIALLY        6. SHARED VOTING POWER
OWNED BY                727,273
EACH              -----------------------------------------
REPORTING           7. SOLE DISPOSITIVE POWER
PERSON                       -0-
WITH              -----------------------------------------
                    8. SHARED DISPOSITIVE POWER
                        727,273
                  -----------------------------------------
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
    PERSON
    727,273
- -----------------------------------------------------------
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ( )
- -----------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.75%
- -----------------------------------------------------------
12. TYPE OF REPORTING PERSON*
    CO
- -----------------------------------------------------------
           *SEE INSTRUCTIONS BEFORE FILLING OUT!






ITEM          1 (a). NAME OF ISSUER Gartner Group, Inc.
- -----------------------------------------------------------
ITEM 1 (b).   ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE
                    OFFICES
   56 Top Gallant Road, Stamford, Connecticut 06904-2212
- -----------------------------------------------------------
ITEM 2 (a).   NAME OF PERSON FILING
   Cognizant Corporation("Cognizant")and its subsidiaries,
   Cognizant Enterprises, Inc. ("CEI"), Nielsen Media Research,
   Inc. ("NMR")and Cognizant Licensing Associates, L.P. ("CLA")
- ----------------------------------------------------------
ITEM 2 (b). ADDRESS OF PRINCIPAL  BUSINESS OFFICE The principal business offices
   of Cognizant  and CEI are located at 200 Nyala Farms,  Westport,  Connecticut
   06880. The principal  business offices of NMR are located at 299 Park Avenue,
   New York, New York 10171.  The principal  business offices of CLA are located
   at Dorfplatz 4, 6330 CHAM Switzerland.
- -----------------------------------------------------------
ITEM 2 (c).   CITIZENSHIP
   Cognizant, CEI and NMR are incorporated under the laws of
   the State of Delaware.  CLA is a limited partnership established
   under the laws of the State of Delaware.
- -----------------------------------------------------------
ITEM 2 (d).   TITLE OF CLASS OF SECURITIES
                    Common Stock, Class A
- -----------------------------------------------------------
ITEM 2 (e).   CUSIP NUMBER
                    366651107
- -----------------------------------------------------------
ITEM 3.
                    Not Applicable
- -----------------------------------------------------------
ITEM 4.       OWNERSHIP
    The following information is provided as of December 31,
    1996:
    (a)  Amount Beneficially Owned
    Cognizant is the owner of record and beneficially of
    31,641,369 shares of Class A Common Stock and a Warrant to purchase 
    60,000 shares of Class A Common Stock.  CEI is the owner of record
    and beneficially of 13,257,728 shares of Class A Common
    Stock.  NMR is the owner of record and beneficially of
    1,972,727 shares of Class A Common Stock and a Warrant to
    purchase 540,000 shares of Class A Common Stock.  CLA is the owner of record
       and beneficially of 727,273 shares of Class A Common Stock. Cognizant, as
       the  owner  of  100% of the  voting  stock  of CEI and NMR and an  83.93%
       interest  in CLA,  may also be  deemed  to be a  beneficial  owner of the
       shares and Warrants held by them, for an aggregate  beneficial  ownership
       by Cognizant of 48,199,097 shares.







(b)  Percent of Class:
     Cognizant - 49.1% (this percentage calculation assumes
        the  conversion  of the  Warrants to purchase  600,000  shares of Common
     Stock)  CEI - 13.6% NMR - 2.6% (this  percentage  calculation  assumes  the
     conversion of the Warrant to purchase 540,000 shares of Common Stock) CLA -
     0.75%

(c)  NUMBER OF SHARES AS TO WHICH  COGNIZANT,  CEI,  NMR and CLA HAVE:  (i) sole
     power to vote or to direct the vote:
           Cognizant -  31,701,369 (includes 60,000 shares issuable pursuant to
            the Warrants)
           CEI -  None
           NMR -  None
              CLA -  None
    (ii)   shared  power to vote or to direct the vote:  Cognizant -  16,497,728
           (includes  540,000  shares  issuable  pursuant to the Warrants) CEI -
           13,257,728 NMR - 2,512,727 (includes 540,000 shares issuable pursuant
           to the Warrants)
              CLA -  727,273
    (iii) sole power to dispose or to direct the disposition of:
           Cognizant - 31,701,369 (includes 60,000 shares issuable             
                pursuant to the Warrants)
           CEI - None
           NMR - None
              CLA - None
    (iv)      shared  power  to  dispose  or  to  direct  the  disposition  of :
              Cognizant - 16,497,728 (includes 540,000 shares issuable pursuant
           to the Warrants) CEI - 13,257,728 NMR - 2,512,727  (includes  540,000
           shares issuable pursuant to the Warrants)
              CLA - 727,273

ITEM 5.  OWNERSHIP OF FIVE PERCENT OR LESS OF CLASS
            Not Applicable
- -----------------------------------------------------------
ITEM 6.  OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF
            ANOTHER PERSON
            Not applicable
- ------------------------------------------------------------







ITEM 7.  IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY
         WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY
         THE PARENT HOLDING COMPANY
         See item 2 (a)
- -----------------------------------------------------------
ITEM 8.  IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE
         GROUP
         Not applicable
- ------------------------------------------------------------
ITEM 9.  NOTICE OF DISSOLUTION OF GROUP
         Not applicable
- ------------------------------------------------------------
ITEM 10.  CERTIFICATION
          Not applicable
- ------------------------------------------------------------






SIGNATURE
- ----------
     After  reasonable  inquiry  and to the best of my  knowledge  and  belief I
certify that the information  set forth in this statement is true,  complete and
correct.

     Dated:  January 12, 1998

                          COGNIZANT CORPORATION


                          By
                             ------------------------------
                             Name:  Kenneth S. Siegel
                             Title:  Senior Vice President,
                           Secretary & General Counsel

                          COGNIZANT ENTERPRISES, INC.


                          By
                             -------------------------------
                              Name: Kenneth S. Siegel
                              Title: Secretary


                          NIELSEN MEDIA RESEARCH, INC.


                          By
                             -------------------------------
                             Name: Kenneth S. Siegel
                             Title: Secretary

                                      COGNIZANT LICENSING ASSOCIATES, L.P.


                                      By
                                         -------------------------------
                                         Ernst Kuhn, on behalf of
                                         the General Partner,
                                         IMS Pharminform Holding, AG











                               AGREEMENT


                                            Westport, CT
                                            January 12, 1998

     Cognizant Corporation ("Cognizant"), Cognizant
Enterprises, Inc. ("CEI"), Nielsen Media Research, Inc.
("NMR")and Cognizant Licensing Associates, L.P.("CLA")
hereby agree to file a joint Schedule 13G under the
Securities Exchange Act of 1934 (the "Act") in connection
with their beneficial ownership of common stock issued by
the Gartner Group, Inc.

     Cognizant, CEI, NMR and CLA state they are all entitled to individually use
Schedule 13G pursuant to Rule 13d-1 (c) of the Act.

     Each of Cognizant,  CEI, NMR and CLA are  responsible for the timely filing
of the  statement  and any  amendments  thereto  and for  the  completeness  and
accuracy of the information  concerning each of them contained therein, but none
is responsible for the  completeness  or accuracy of the information  concerning
the other.

                          COGNIZANT CORPORATION


                          By:
                             -----------------------------
                             Name:  Kenneth S. Siegel,
                                         Title: Senior Vice President,
                           Secretary & General Counsel


                           COGNIZANT ENTERPRISES, INC.


                           By:
                              ----------------------------
                              Name:  Kenneth S. Siegel
                              Title: Secretary


                            NIELSEN MEDIA RESEARCH, INC.


                            By:
                               ------------------------------
                               Name:  Kenneth S. Siegel
                               Title: Secretary

                                      COGNIZANT LICENSING ASSOCIATES, L.P.


                                      By
                                         -------------------------------
                                         Ernst Kuhn,on behalf of
                                         the General Partner,
                                         IMS Pharminform Holding, AG