The National Crime Survey (NCS) has been redesigned to reflect population changes from the 1980 Census. The final report of the CPS/NCS phase-in work group (Document No. 26 dated May 16, 1983) describes several alternative phase-in plans. Plan B in this report has been selected for use. A description of the plan and the reasons for its selection are contained in an SMD Draft Memorandum entitled "NCS Redesign: Plans for Measuring the Effect of Phase-in of New Sample Areas" (undated). A discussion of the major factors which may affect NCS estimates and several possible approaches to estimating their effect are given.