EXHIBIT 99.1


LETTER OF QUALITY ASSURANCE BY ARTHUR ANDERSEN LLP

Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549

Ladies and Gentlemen:

Arthur Andersen LLP ("Andersen") has represented to Forrester Research, Inc.
that the audit was subject to Andersen's quality control system for the U.S.
accounting and auditing practice to provide reasonable assurance that the
engagement was conducted in compliance with professional standards and that
there was appropriate continuity of Andersen personnel working on the audit,
availability of national office consultation, and availability of personnel at
foreign affiliates of Andersen to conduct the relevant portions of the audit.

                                   /s/ Forrester Research, Inc.


Boston, Massachusetts
March 20, 2002