WASHINGTON, D.C. 20549


                                   SCHEDULE TO
                                 (RULE 14d-100)

                             TENDER OFFER STATEMENT
                  UNDER SECTION 14(d)(1) OR SECTION 13(e)(1) OF
                      THE SECURITIES EXCHANGE ACT OF 1934
                                (AMENDMENT NO. 5)


                          GIGA INFORMATION GROUP, INC.
                       (Name Of Subject Company (Issuer))


                            FORRESTER RESEARCH, INC.

                           WHITCOMB ACQUISITION CORP.
                      (Names of Filing Persons (Offerors))

                    COMMON STOCK, PAR VALUE $0.001 PER SHARE
                         (Title of Class of Securities)

                      (CUSIP Number of Class of Securities)


                               Tim Moynihan, Esq.
                            Forrester Research, Inc.
                              400 Technology Square
                               Cambridge, MA 02139
                            Telephone: (617) 613-6000
            (Name, address and telephone number of person authorized
       to receive notices and communications on behalf of filing persons)


                                   COPIES TO:

                             Keith F. Higgins, Esq.
                               Ann L. Milner, Esq.
                                  Ropes & Gray
                             One International Place
                           Boston, Massachusetts 02110
                            Telephone: (617) 951-7000

                            CALCULATION OF FILING FEE

Transaction Valuation*                                    Amount Of Filing Fee**
- ----------------------                                    ----------------------
     $60,000,000                                                $5,520

*        Estimated solely for purposes of calculating amount of filing fee in
         accordance with Rule 0-11(d) under the Securities Exchange Act of 1934,
         as amended (the "Exchange Act"). The calculation of the transaction
         valuation is based on 14,064,000 shares of common stock of Giga
         Information Group, Inc. ("Giga") at a purchase price of $4.75 per
         share. Such number includes all outstanding shares as of January 20,
         2003, and assumes the exercise of all in-the-money stock options and
         warrants to purchase common stock of Giga which are exercisable in
         connection with the transaction.

**       Previously paid.

[ ]      Check the box if any part of the fee is offset as provided by Rule
         0-11(a)(2) and identify the filing with which the offsetting fee was
         previously paid. Identify the previous filing by registration statement
         number or the Form or Schedule and the date of its filing.

Amount Previously Paid:                                                    N/A
Form or Registration No.:                                                  N/A
Filing Party:                                                              N/A
Date Filed:                                                                N/A

[ ]      Check the box if the filing relates to preliminary communications
         made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the
statement relates:

[X]      third-party tender offer subject to Rule 14d-1.

[ ]      issuer tender offer subject to Rule 13e-4.

[ ]       going-private transaction subject to Rule 13e-3.

[ ]       amendment to Schedule 13D under Rule 13d-2.

          Check the following box if the filing is a final amendment reporting
          the results of the tender offer: [ ]


         This Amendment No. 5 amends and supplements the Tender Offer Statement
on Schedule TO (the "Schedule TO") filed with the Securities and Exchange
Commission on January 27, 2003 and amended on January 28, 2003, February 13,
2003, February 19, 2003 and February 24, 2003 by Forrester Research, Inc., a
Delaware corporation ("Parent"), and Whitcomb Acquisition Corp., a Delaware
corporation and a wholly owned subsidiary of Parent (the "Purchaser"). The
Schedule TO relates to the offer by the Purchaser to purchase all the
outstanding shares of common stock, $0.001 par value per share (the "Shares"),
of Giga Information Group, Inc., a Delaware corporation (the "Company"),
together with the associated rights to purchase Series A Junior Preferred Stock,
par value $0.001 per share, issued pursuant to the Rights Agreement dated as of
February 18, 2000 between the Company and American Stock Transfer & Trust Co.,
at a purchase price of $4.75 per Share, net to the seller in cash, less any
required withholding taxes and without interest thereon, upon the terms and
subject to the conditions set forth in the related offer to purchase dated
January 27, 2003 (the "Offer to Purchase"), and in the related letter of
transmittal. Capitalized terms used and not otherwise defined herein have the
meanings assigned thereto in the Schedule TO.


         Items 4, 8 and 11 of the Schedule TO are hereby amended to add the

         At 12:00 midnight, New York City time, on Monday, February 24, 2003,
the initial offering period expired. Based upon preliminary information from the
Depositary, 10,336,913 Shares were tendered into the Offer (including 1,554,400
Shares tendered by Notice of Guaranteed Delivery), which represents
approximately 93.4% of the Company's outstanding Shares (based upon 11,061,758
Shares outstanding as of February 24, 2003). The Shares tendered also represent
approximately 66.3% of the outstanding Shares on a fully-diluted basis (based on
15,586,118 Fully-Diluted Shares as of January 20, 2003), thereby satisfying the
condition to the Offer that more than 50% of the Fully-Diluted Shares be
tendered. The Purchaser has accepted all such tendered Shares for payment and
will make payment promptly to the Depositary for the accepted Shares.

         On February 25, 2003, Parent issued a press release announcing the
completion of the initial offering period and acceptance of the Shares for
payment, the full text of which is filed as Exhibit (a)(10) to this Schedule TO,
which is incorporated by referenced herein.


(a)(10)  Press release issued by Parent on February 25, 2003.


         After due 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.

                                        WHITCOMB ACQUISITION CORP.

                                        By:  /s/ Tim Moynihan
                                             Name:  Tim Moynihan
                                             Title:  President

                                        FORRESTER RESEARCH, INC.

                                        By:  /s/ Warren Hadley
                                             Name:  Warren Hadley
                                             Title:  Chief Financial Officer

Dated: February 25, 2003

                                  EXHIBIT INDEX

Exhibit No.                Description
- -----------                -----------

(a)(10)                    Press release issued by Parent on February 25, 2003.

                                                                 Exhibit (a)(10)



         CAMBRIDGE, Mass., February 25, 2003 . . . Forrester Research, Inc.
(Nasdaq: FORR), a leading provider of research and analysis on emerging
technologies, and Giga Information Group, Inc. (OTCBB: GIGX), a leading global
technology advisory firm, today announced the completion of Forrester's cash
tender offer for all shares of common stock of Giga at a price of $4.75 per

The tender offer expired at midnight New York City time on February 24, 2003.
Based on preliminary information provided by EquiServe Trust Company, N.A., the
depositary for the offer, approximately 10,336,913 shares of Giga's common stock
were tendered into the offer (including 1,554,400 shares tendered by notice of
guaranteed delivery), which represents 93.4% of Giga's outstanding common stock
(based upon 11,061,758 shares outstanding as of February 24, 2003). Whitcomb
Acquisition Corp., a wholly owned subsidiary of Forrester through which the
tender offer was made, has accepted for payment all validly tendered shares and
will make payment promptly to the depositary for the accepted shares.

Forrester intends to acquire the remaining shares of Giga common stock in a
second-step merger in which all remaining Giga stockholders who did not tender
their shares in the tender offer will receive the same $4.75 per share in cash
paid in the tender offer. Because Forrester acquired greater than 90% of the
outstanding Giga shares, the merger will be completed without a stockholder
vote. Forrester will mail relevant information to Giga stockholders who did not
tender their shares in the tender offer on how to receive payment for their

Forrester Research identifies and analyzes trends in emerging technology and
their impact on business. Forrester's WholeView((TM)) Research, Strategic
Services, and Events help $1 billion-plus clients understand how technology
change affects their customers, strategy, and technology investment. Established
in 1983, Forrester is headquartered in Cambridge, Mass. For additional
information, visit www.forrester.com.

Giga is a leading global technology advisory firm that provides objective
research, pragmatic advice, and personalized consulting. Emphasizing close
interaction between analyst and client, Giga enables companies to make better
strategic decisions that maximize technology investments and achieve business
results. Founded in 1995, Giga is headquartered in Cambridge, Mass. and has
offices worldwide. For additional information, visit www.gigaweb.com.

This press release contains forward-looking statements within the meaning of the
Private Securities Litigation Reform Act of 1995. These statements include, but
are not limited to, Forrester's statements about its acquisition of Giga. These
statements are based on Forrester's current plans and expectations and involve
risks and uncertainties that could cause actual future activities and results of
operations to be materially different from those set forth in the
forward-looking statements. Important factors that could cause actual future
activities and results to differ include, among others, Forrester's ability to
anticipate business and economic conditions, market trends, competition, the
need to retain professional staff, possible variations in Forrester's quarterly
operating results, Forrester's ability to successfully complete the acquisition
of Giga and integrate Giga into Forrester's operations, Forrester's dependence
on renewals

of its membership-based research services and on key personnel, and risks
associated with Forrester's ability to offer new products and services.
Forrester Research undertakes no obligation to update publicly any
forward-looking statements, whether as a result of new information, future
events, or otherwise. For further information, please refer to Forrester's
reports and filings with the Securities and Exchange Commission.

                                     - ### -

Contact:                                     Contact:
Kimberly Maxwell                             Christina Thirkell
Director, Investor Relations                 Manager, Public Relations
Forrester Research, Inc.                     Giga Information Group, Inc.
+ 1 617/613-6234                             + 1 617/577-4965

Mariko Zapf
Manager, Public Relations
Forrester Research, Inc.
+ 1 617/613-6255

(C) 2003, Forrester Research, Inc. All rights reserved. Forrester and WholeView
are trademarks of Forrester Research, Inc.