<PAGE>

                                                                    EXHIBIT 31.2

                  CERTIFICATION BY THE CHIEF FINANCIAL OFFICER
            PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

      I, Eric F. Lundberg, certify that:

1.    I have reviewed this quarterly report on Form 10-Q of American Lawyer
      Media, Inc.;

2.    Based on my knowledge, this quarterly report does not contain any untrue
      statement of a material fact or omit to state a material fact necessary to
      make the statements made, in light of the circumstances under which such
      statements were made, not misleading with respect to the period covered by
      this quarterly report;

3.    Based on my knowledge, the financial statements, and other financial
      information included in this quarterly report, fairly present in all
      material respects the financial condition, results of operations and cash
      flows of the registrant as of, and for, the periods presented in this
      quarterly report;

4.    The registrant's other certifying officer(s) and I are responsible for
      establishing and maintaining disclosure controls and procedures (as
      defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant
      and have:

            a) Designed such disclosure controls and procedures to ensure that
            material information relating to the registrant, including its
            consolidated subsidiaries, is made known to us by others within the
            registrant, particularly during the period in which this quarterly
            report is being prepared; and

            b) Evaluated the effectiveness of the registrant's disclosure
            controls and procedures and presented in this quarterly report our
            conclusions about the effectiveness of the disclosure controls and
            procedures, as of the end of the period covered by this quarterly
            report based on such evaluation; and

            c) Disclosed in this quarterly report any change in the registrant's
            internal control over financial reporting that occurred during the
            registrant's most recent fiscal quarter that has materially
            affected, or is reasonably likely to materially affect, the
            registrant's internal control over financial reporting.

5.    The registrant's other certifying officers and I have disclosed, based on
      our most recent evaluation of internal control over financial reporting,
      to the registrant's auditors and the audit committee of the registrant's
      board of directors (or persons performing the equivalent functions):

            a) All significant deficiencies and material weaknesses in the
            design or operation of internal control over financial reporting
            which are reasonably likely to adversely affect the registrant's
            ability to record, process, summarize and report financial
            information; and

<PAGE>

            b) Any fraud, whether or not material, that involves management or
            other employees who have a significant role in the registrant's
            internal control over financial reporting.

Date:  August 13, 2004

  /s/ ERIC F. LUNDBERG
-------------------------------------
Eric F. Lundberg
Vice President and Chief Financial Officer