UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549

                                  SCHEDULE 13G


                   Under the Securities Exchange Act of 1934

                              (Amendment No. 1 )*


                              Avid Technology, Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)

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

                                    05367P100
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                               December 31, 2002
--------------------------------------------------------------------------------
            (Date of Event Which Requires Filing of this Statement)


Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

                                [x] Rule 13d-1(b)

                                [_] Rule 13d-1(c)

                                [_] Rule 13d-1(d)


----------

* 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 the
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).



                               Page 1 of 10 pages

CUSIP No.05367P100                    13G                     Page 2 of 10 Pages


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

       Liberty Wanger Asset Management, L.P. 36-3820584

--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [ ]
       Not Applicable                                            (b)  [ ]

--------------------------------------------------------------------------------
3    SEC USE ONLY



--------------------------------------------------------------------------------
4    CITIZENSHIP OR PLACE OF ORGANIZATION

       Delaware

--------------------------------------------------------------------------------
  NUMBER OF    5    SOLE VOTING POWER

   SHARES             None

               -----------------------------------------------------------------
BENEFICIALLY   6    SHARED VOTING POWER

  OWNED BY            1,925,000

               -----------------------------------------------------------------
    EACH       7    SOLE DISPOSITIVE POWER

  REPORTING           None

               -----------------------------------------------------------------
   PERSON      8    SHARED DISPOSITIVE POWER

    WITH              1,925,000

--------------------------------------------------------------------------------
9    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       1,925,000

--------------------------------------------------------------------------------
10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

       Not Applicable                                                    [ ]

--------------------------------------------------------------------------------
11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

       7.3%

--------------------------------------------------------------------------------
12   TYPE OF REPORTING PERSON*

       IA

--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No.05367P100                    13G                     Page 3 of 10 Pages


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

       WAM Acquisition GP, Inc.

--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [ ]
       Not Applicable                                            (b)  [ ]

--------------------------------------------------------------------------------
3    SEC USE ONLY



--------------------------------------------------------------------------------
4    CITIZENSHIP OR PLACE OF ORGANIZATION

       Delaware

--------------------------------------------------------------------------------
  NUMBER OF    5    SOLE VOTING POWER

   SHARES             None

               -----------------------------------------------------------------
BENEFICIALLY   6    SHARED VOTING POWER

  OWNED BY            1,925,000

               -----------------------------------------------------------------
    EACH       7    SOLE DISPOSITIVE POWER

  REPORTING           None

               -----------------------------------------------------------------
   PERSON      8    SHARED DISPOSITIVE POWER

    WITH              1,925,000

--------------------------------------------------------------------------------
9    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       1,925,000

--------------------------------------------------------------------------------
10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

       Not Applicable                                                    [ ]

--------------------------------------------------------------------------------
11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

       7.3%

--------------------------------------------------------------------------------
12   TYPE OF REPORTING PERSON*

       CO

--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!

CUSIP No.05367P100                    13G                     Page 4 of 10 Pages


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

       Liberty Acorn Trust

--------------------------------------------------------------------------------
2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [ ]
       Not Applicable                                            (b)  [ ]

--------------------------------------------------------------------------------
3    SEC USE ONLY



--------------------------------------------------------------------------------
4    CITIZENSHIP OR PLACE OF ORGANIZATION

       Massachusetts

--------------------------------------------------------------------------------
  NUMBER OF    5    SOLE VOTING POWER

   SHARES             None

               -----------------------------------------------------------------
BENEFICIALLY   6    SHARED VOTING POWER

  OWNED BY            1,900,000

               -----------------------------------------------------------------
    EACH       7    SOLE DISPOSITIVE POWER

  REPORTING           None

               -----------------------------------------------------------------
   PERSON      8    SHARED DISPOSITIVE POWER

    WITH              1,900,000

--------------------------------------------------------------------------------
9    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       1,900,000

--------------------------------------------------------------------------------
10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

       Not Applicable                                                    [ ]

--------------------------------------------------------------------------------
11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

       7.2%

--------------------------------------------------------------------------------
12   TYPE OF REPORTING PERSON*

       IV

--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!

Item 1(a)   Name of Issuer:

                  Avid Technology, Inc.

Item 1(b)   Address of Issuer's Principal Executive Offices:

                  Avid Technology Park
                  One Park West
                  Tewksbury, MA  01876

Item 2(a)   Name of Person Filing:

                  Liberty Wanger Asset Management, L.P. ("WAM")
                  WAM Acquisition GP, Inc., the general partner of WAM
                     ("WAM GP")
                  Liberty Acorn Trust ("Acorn")

Item 2(b)   Address of Principal Business Office:

                  WAM, WAM GP and Acorn are all located at:

                  227 West Monroe Street, Suite 3000
                  Chicago, Illinois  60606

Item 2(c)   Citizenship:

                  WAM is a Delaware limited partnership; WAM GP is a Delaware
                  corporation; and Acorn is a Massachusetts business trust.

Item 2(d)   Title of Class of Securities:

                  Common Stock

Item 2(e)   CUSIP Number:

                  05367P100

Item 3      Type of Person:

                  (d)   Acorn is an Investment Company under section 8 of the
                        Investment Company Act.

                  (e)   WAM is an Investment Adviser registered under section
                        203 of the Investment Advisers Act of 1940; WAM GP is
                        the General Partner of the Investment Adviser.



                               Page 5 of 10 pages

Item 4   Ownership (at December 31, 2002):

                  (a)   Amount owned "beneficially" within the meaning of rule
                        13d-3:

                        1,925,000


                  (b)   Percent of class:

                        7.3% (based on 26,526,815 shares outstanding as of
                        November 5, 2002).


                  (c)   Number of shares as to which such person has:

                        (i)   sole power to vote or to direct the vote: none


                        (ii)  shared power to vote or to direct the vote:
                              1,925,000


                        (iii) sole power to dispose or to direct the disposition
                              of: none


                        (iv)  shared power to dispose or to direct
                              disposition of: 1,925,000



Item 5   Ownership of Five Percent or Less of a Class:

                  Not Applicable

Item 6   Ownership of More than Five Percent on Behalf of Another Person:

                  The shares reported herein have been acquired on behalf of
                  discretionary clients of WAM, including Acorn. Persons other
                  than WAM and WAM GP are entitled to receive all dividends
                  from, and proceeds from the sale of, those shares. Acorn is
                  the only such person known to be entitled to all dividends
                  from, and all proceeds from the sale of, shares reported
                  herein to the extent of more than 5% of the class.

Item 7   Identification and Classification of the Subsidiary Which Acquired
         the Security Being Reported on by the Parent Holding Company:

                  Not Applicable

Item 8   Identification and Classification of Members of the Group:

                  Not Applicable

Item 9   Notice of Dissolution of Group:

                  Not Applicable



                               Page 6 of 10 pages

Item 10   Certifications:

                By signing below I certify that, to the best of my knowledge
          and belief, the securities referred to above were acquired and are
          held in the ordinary course of business and were not acquired and
          not held for the purpose of or with the effect of changing or
          influencing the control of the issuer of the securities and were not
          acquired and are not held in connection with or as a participant in
          any transaction having that purpose or effect.


                               Page 7 of 10 pages

                                    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.

Date: February 10, 2003

                  The undersigned corporation, on the date above written, agrees
                  and consents to the joint filing on its behalf of this
                  Schedule 13G in connection with its beneficial ownership of
                  the security reported herein.


                                    WAM Acquisition GP, Inc.
                                      for itself and as general partner of
                                      LIBERTY WANGER ASSET
                                      MANAGEMENT, L.P.



                                    By:  /s/ Bruce H. Lauer
                                         ---------------------------------------
                                             Bruce H. Lauer
                                             Senior Vice President and Secretary

                  The undersigned corporation, on the date above written, agrees
                  and consents to the joint filing on its behalf of this
                  Schedule 13G in connection with its beneficial ownership of
                  the security reported herein.


                                    LIBERTY ACORN TRUST



                                    By:  /s/ Bruce H. Lauer
                                         ---------------------------------------
                                             Bruce H. Lauer
                                             Vice President, Treasurer and
                                             Secretary


                               Page 8 of 10 pages

                                  Exhibit Index
                                  -------------

Exhibit 1               Joint Filing Agreement dated as of February 10, 2003 by
                        and among Liberty Wanger Asset Management, L.P., WAM
                        Acquisition GP, Inc. and Liberty Acorn Trust



                               Page 9 of 10 pages