EXHIBIT 21 SIGNIFICANT SUBSIDIARIES NATIONAL COMPUTER SYSTEMS, INC. STATE OR OTHER JURISDICTION OF NAME UNDER WHICH NAME OF SUBSIDIARY INCORPORATION SUBSIDIARY DOES BUSINESS - ------------------ ------------- ------------------------ Interpretive Scoring Minnesota National Computer Systems, Inc. Systems, Inc. NCS Assessments Professional Assessment Services Division of National Computer Systems, Inc. Macro Educational California National Computer Systems, Inc. Systems, Inc. Education Systems and Services Division of National Computer Systems, Inc. Note: No other subsidiary of National Computer Systems, Inc. meets the conditions to be deemed a significant subsidiary.