Washington, D.C. 20549

                                  SCHEDULE 13G

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

                             Forrester Research, Inc
                                (Name of Issuer)

                                  COMMON STOCK
                         (Title of Class of Securities)

                                 (CUSIP Number)

Check the following box if a fee is being paid with this statement |_|.(A fee is
not required only if the filing 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 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

CUSIP No. 346563109 13G Page 2 of 4 Pages - -------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON CRAMER ROSENTHAL MCGLYNN, LLC IRS ID# 13-3156718 - -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) |_| (b) |X| - -------------------------------------------------------------------------------- 3 SEC USE ONLY - -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION INCORPORATED IN THE STATE OF NEW YORK - -------------------------------------------------------------------------------- 5 SOLE VOTING POWER NUMBER OF 674,000 SHARES -------------------------------------------------------- BENEFICIALLY 6 SHARED VOTING POWER OWNED BY EACH 395,300 REPORTING -------------------------------------------------------- PERSON 7 SOLE DISPOSITIVE POWER WITH 688,500 -------------------------------------------------------- 8 SHARED DISPOSITIVE POWER 395,300 - -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,083,800 - -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* - -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 4.70% - -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* IA - -------------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT

Page 3 of 4 Pages Item 1. (a) Name of Issuer: Forrester Research, Inc (b) Address of Issuer's Principal Executive Offices: 400 TECHNOLOGY SQUARE CAMBRIDGE MA 02139 Item 2. (a) Name of Person Filing: CRAMER ROSENTHAL MCGLYNN, LLC (b) Address of Principal Business Office: 520 Madison Avenue, New York, New York 10022 (c) Citizenship: INCORPORATED IN THE STATE OF NEW YORK (d) Title of Class of Securities: COMMON STOCK (e) CUSIP Number: 346563109 Item 3. If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b), check whether the person filing is a: (a) |_| Broker or Dealer registered under Section 15 of the Act (b) |_| Bank as defined in section 3(a)(6) of the Act (c) |_| Insurance Company as defined in section 3(a)(19) of the Act (d) |_| Investment Company registered under section 8 of the Investment Company Act (e) [X] Investment Adviser registered under section 203 of the Investment Advisers Act of 1940 (f) |_| Employee Benefit Plan, Pension Fund which is subject to the provisions of the Employee Retirement Income Security Act of 1974 or Endowment Fund; see Section 240.13d-1(b)(1)(ii)(F) (g) |_| Parent Holding Company, in accordance with section 240.13d-1(b)(1)(ii)(G) (h) |_| Group, in accordance with Section 240.13d-1(b)(1)(ii)(H)

Page 4 of 4 Pages Item 4. Ownership. Item 5. Ownership of Five Percent or Less of a Class. ONE CLASS OF STOCK 4.70% 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. NOT APPLICABLE Item 8. Identification and Classification of Members of the Group. NOT APPLICABLE Item 9. Notice of Dissolution of Group. NOT APPLICABLE Item 10. Certification. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purpose or effect. Signature. /s/ Elizabeth Coley -------------------------------- General Counsel 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: 1/10/03