Exhibit (a)(8)


This announcement is neither an offer to purchase nor a solicitation of an offer
to sell Shares (as defined below). The Offer (as defined below) is made solely
by the Offer to Purchase, dated January 27, 2003 (the "Offer to Purchase"), and
the related Letter of Transmittal, and is being made to all holders of Shares.
The Offer is not being made to (nor will tenders be accepted from or on behalf
of) holders of Shares in any jurisdiction in which the making of the Offer or
the acceptance thereof would not be in compliance with the laws of such
jurisdiction or any administrative or judicial action pursuant thereto.

Notice of Offer to Purchase for Cash
All Outstanding Shares of Common Stock
of
Giga Information Group, Inc.
at
$4.75 Net Per Share
by
Whitcomb Acquisition Corp.
a wholly owned subsidiary of
Forrester Research, Inc.

Whitcomb Acquisition Corp., a Delaware corporation ("Purchaser") and a wholly
owned subsidiary of Forrester Research, Inc., a Delaware corporation
("Forrester"), is offering to purchase all of the issued and outstanding shares
of Common Stock, par value $0.001 per share (the "Shares"), of Giga Information
Group, Inc., a Delaware corporation ("Giga"), together with the associated
rights (the "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 (the "Rights Agreement") between the Company and American Stock
Transfer & Trust Co., for $4.75 per Share, net to the seller in cash (the "Offer
Price"), upon the terms and subject to the conditions set forth in the Offer to
Purchase and in the related Letter of Transmittal (which together, along with
any amendments or supplements thereto, constitute the "Offer"). Stockholders who
tender directly to the Depositary (as defined below) will not be obligated to
pay brokerage fees or commissions or, subject to Instruction 6 of the Letter of
Transmittal, stock transfer taxes, if any, on the purchase of Shares by
Purchaser pursuant to the Offer. Stockholders who hold their Shares through a
broker or bank should consult such institution as to whether it charges any
service fees or commissions. Following consummation of the Offer, Forrester and
Purchaser intend to effect the merger described below. Unless the context
requires otherwise, all references to the Shares herein include the associated
Rights, and all references to the Rights include the benefits that may inure to
the holders of the Rights pursuant to the Rights Agreement.

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
TIME, ON MONDAY, FEBRUARY 24, 2003, UNLESS THE OFFER IS EXTENDED.

The Offer is being made pursuant to an Agreement and Plan of Merger (the "Merger
Agreement"), dated as of January 20, 2003 by and among Forrester, Purchaser and
Giga, pursuant to which, as soon as practicable after the completion of the
Offer and satisfaction or waiver of all conditions to the Merger (as defined
below), Purchaser will be merged with and into Giga and Giga will continue as
the surviving corporation and

will become a wholly owned subsidiary of Forrester. The merger, as effected
pursuant to the immediately preceding sentence, is referred to herein as the
"Merger." At the effective time of the Merger (the "Effective Time"), each Share
then outstanding (other than Shares held by Forrester, Purchaser or any other
wholly owned subsidiary of Forrester or by dissenting stockholders who have
properly exercised their appraisal rights) will be canceled and extinguished and
converted into the right to receive the Offer Price in cash, payable to the
holder thereof, without interest. If Purchaser acquires, pursuant to the Offer,
at least 90% of the then issued and outstanding Shares, Purchaser intends to
effect the Merger without a vote of the stockholders of Giga pursuant to Section
253 of the Delaware General Corporation Law.

Giga's board of directors (1) has unanimously approved the Merger Agreement and
the transactions contemplated thereby, including the Offer and the Merger, (2)
has unanimously determined that the terms of the Offer and the Merger are fair,
from a financial point of view, to the stockholders of Giga and that the Merger
is advisable, and (3) unanimously recommends that stockholders of Giga accept
the Offer and tender their Shares pursuant to the Offer.

The Offer is conditioned upon, among other things, there being validly tendered
and not withdrawn prior to the Expiration Date (as defined below) that number of
Shares which constitutes more than 50% of the outstanding Shares on a fully
diluted basis on the date Shares are accepted for payment (the "Minimum Tender
Condition"). As used herein, "fully diluted basis" means the number of Shares
outstanding, together with the number of Shares which Giga may be required to
issue pursuant to vested options, warrants or other convertible securities or
obligations outstanding at that date under employee stock or similar benefits
plans or otherwise. The Offer is also subject to other terms and conditions
described in Section 14 of the Offer to Purchase.

Alliant Partners ("Alliant"), Giga's financial advisor, has delivered to Giga
its written opinion, dated January 20, 2003, to the effect that, as of that date
and based on and subject to the matters stated in such opinion, the
consideration to be received by the stockholders of Giga in the Offer and the
Merger is fair, from a financial point of view, to such stockholders. A copy of
the written opinion of Alliant is contained in Giga's Solicitation/
Recommendation Statement on Schedule 14D-9 filed with the Securities and
Exchange Commission in connection with the Offer, a copy of which is being
furnished to the stockholders of Giga concurrently with the Offer to Purchase.

For purposes of the Offer, Purchaser will be deemed to have accepted for
payment, and thereby purchased, Shares validly tendered and not withdrawn if, as
and when Purchaser gives oral or written notice to EquiServe Trust Company, N.A.
(the "Depositary") of Purchaser's acceptance for payment of such Shares pursuant
to the Offer. Payment for Shares accepted for payment pursuant to the Offer will
be made by deposit of the purchase price therefor with the Depositary, which
will act as agent for the tendering stockholders for the purposes of receiving
payments from Purchaser and transmitting such payments to the tendering
stockholders whose Shares have been accepted for payment. In all cases, payment
for Shares tendered and accepted for payment pursuant to the Offer will be made
only after timely receipt by the Depositary of (a) certificates for (or a timely
Book-Entry Confirmation (as defined in the Offer to Purchase) with respect to)
such Shares, (b) a Letter of Transmittal, properly completed and duly executed,
with any required signature guarantees (or, in the case of a book-entry
transfer, an Agent's

Message (as defined in the Offer to Purchase)), and (c) any other documents
required by the Letter of Transmittal. Accordingly, tendering Stockholders may
be paid at different times depending upon when certificates for, or Book-Entry
Confirmations with respect to, the Shares are actually received by the
Depositary. Under no circumstances will interest be paid on the purchase price
to be paid by Purchaser for the tendered Shares, regardless of any extension of
the Offer or any delay in making such payment. Tenders of Shares made pursuant
to the Offer are irrevocable, except that Shares tendered pursuant to the Offer
may be withdrawn pursuant to the procedures set forth below at any time prior to
the Expiration Date and unless such Shares have already been accepted for
payment by Purchaser pursuant to the Offer, may also be withdrawn at any time
after March 28, 2003, as described in Section 3 of the Offer to Purchase.

For a withdrawal to be effective, a written or facsimile transmission notice of
withdrawal must be timely received by the Depositary at one of its addresses set
forth on the back cover of the Offer to Purchase. Any such notice of withdrawal
must specify the name of the person who tendered the Shares to be withdrawn, the
number of Shares to be withdrawn and the name of the registered holder of such
Shares, if different from that of the person who tendered such Shares. If
certificates evidencing Shares to be withdrawn have been delivered or otherwise
identified to the Depositary, then, prior to the physical release of such
certificates, the serial numbers shown on the particular certificates to be
withdrawn must be submitted to the Depositary, and the signature(s) on the
notice of withdrawal must be guaranteed by an Eligible Institution (as defined
in Section 3 of the Offer to Purchase), unless such Shares have been tendered
for the account of an Eligible Institution. If Shares have been tendered
pursuant to the procedures for book-entry tender as set forth in Section 2 of
the Offer to Purchase, any notice of withdrawal must also specify the name and
number of the account at the Book-Entry Transfer Facility (as defined in the
Offer to Purchase) to be credited with the withdrawn Shares and otherwise comply
with the Book-Entry Transfer Facility's procedures. Withdrawals of tenders of
Shares may not be rescinded and any Shares properly withdrawn will thereafter be
deemed not to have been validly tendered for purposes of the Offer. However,
withdrawn Shares may be re-tendered at any time prior to the Expiration Date by
following one of the procedures described in Section 2 of the Offer to Purchase.

The term "Expiration Date" means 12:00 midnight, New York City time, on February
24, 2003 unless and until Purchaser, in accordance with the terms of the Merger
Agreement, extends the period for which the Offer is open, in which event the
term "Expiration Date" will mean the latest time and date on which the Offer, as
so extended, expires.

All questions as to the form and validity (including, without limitation, time
of receipt) of notices of withdrawal will be determined by Purchaser, in its
sole discretion, whose determination shall be final and binding. None of
Forrester, Purchaser, the Depositary, MacKenzie Partners, Inc. (the "Information
Agent"), or any other person will be under any duty to give notification of any
defects or irregularities in any notice of withdrawal or incur any liability for
failure to give such notification.

Subject to the terms and conditions of the Merger Agreement, including the
parties' right to terminate the Merger Agreement if Purchaser has not purchased
Shares pursuant to the Offer on or before April 30, 2003: (a) Purchaser may
extend the Offer for such period as Purchaser determines if any of the
conditions to Purchaser's obligation to purchase Shares are not satisfied or
waived as of the Expiration Date of the Offer, provided that

such extension will be in increments of not more than five business days if only
the Minimum Tender Condition is not satisfied; (b) Purchaser may also extend the
offer for any period required by any rule, regulation, interpretation or
position of the Securities and Exchange Commission or its staff that is
applicable to the offer; (c) Giga may require Purchaser to extend the offer for
additional periods to be determined by Purchaser if (i) the Minimum Tender
Condition is the only condition that is not satisfied or waived at the
Expiration Date, (ii) the waiting periods under applicable antitrust laws have
not expired or been terminated, or (iii) Giga fails to perform or comply with
its obligations, covenants or agreements under the Merger Agreement and the cure
period relating to such failure has not expired; and (d) if Giga delivers a
notice of a superior acquisition proposal to Forrester within three business
days of the initial Expiration Date, Purchaser will extend the Offer for at
least three business days. In addition, if at the Expiration Date of the Offer
all of the conditions to the Offer have been satisfied or waived, Purchaser may
elect to provide a "subsequent offering period" of up to 20 business days in
accordance with Rule 14d-11 under the Securities and Exchange Act of 1934, as
amended (the "Exchange Act"). Oral or written notice of any extension of the
Expiration Date or the provision of a subsequent offering period would be given
to the Depositary and a public announcement would be made by no later than 9:00
a.m., New York City time, on the next business day after the previously
scheduled expiration date. During an extension, all Shares previously tendered
and not withdrawn would remain subject to the Offer, subject to the right of a
tendering stockholder to withdraw such stockholder's Shares. During a subsequent
offering period, stockholders would not be able to withdraw Shares previously
tendered in the Offer and stockholders would not be able to withdraw Shares
tendered during the subsequent offering period.

The receipt by a stockholder of cash for Shares pursuant to the Offer and the
Merger will be a taxable transaction for United States federal income tax
purposes, and may also be a taxable transaction under applicable state, local or
foreign tax laws. All stockholders are urged to consult with their own tax
advisors as to the particular tax consequences to them of the Offer and the
Merger.

The information required to be disclosed by paragraph (d)(1) of Rule 14d-6 under
the Exchange Act is contained in the Offer to Purchase and is incorporated
herein by reference.

Giga has provided Purchaser with mailing labels containing the names and
addresses of all record holders of Shares and with security position listings of
Shares held in stock depositories, together with all other available listings
and computer files containing names, addresses and security position listings of
record holders and beneficial owners of Shares. The Offer to Purchase, the
related Letter of Transmittal and other relevant documents will be mailed to
record holders of Shares, will be furnished (for subsequent transmittal to
beneficial owners of Shares) to the brokers, dealers, commercial banks, trust
companies and others whose names, or the names of whose nominees, appear on
these lists and may be mailed directly to beneficial owners.

The Offer to Purchase and the related Letter of Transmittal contain important
information which should be read carefully before any decision is made with
respect to the Offer.

Questions and requests for assistance or additional copies of the Offer to
Purchase, Letter of Transmittal and any other tender offer documents may be
directed to the Information Agent at its telephone number and location listed
below, and copies will be furnished at

Purchaser's expense. Purchaser will not pay fees to any broker or dealer or
other person (other than the Information Agent and the Depositary) for
soliciting tenders of Shares pursuant to the Offer.

The Information Agent for the Offer is:
[MACKENZIE LOGO]
105 Madison Avenue
New York, New York 10016
Banks and Brokers call collect: (212) 929-5500
All others call toll-free: (800) 322-2885
Email: proxy@mackenziepartners.com
January 27, 2003