EXHIBIT 23 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our reports included in this Form 10-K, into the Company's previously filed Registration Statements on Form S-8, Registration Numbers 33-80417, 333-59441, 333-53753, 333-39159, and 333-02979. /s/ ARTHUR ANDERSEN LLP Pittsburgh, Pennsylvania March 28, 2002