This report provides users of data from the Second International Mathematics Study with a summary of the survey procedures used by participating countries. The introductory chapter includes definitions, cross-sectional and longitudinal components, and recommended sampling procedures. Chapter 2 presents national population definitions and sampling procedures for the 20 countries surveying Population A (grade 8), while chapter 3 presents corresponding information for the 15 countries surveying Population B (grade 12). Response rates for each population are considered in chapters 4 and 5 and representativeness of the sample is the focus in chapters 6 and 7. The distribution of rotated forms is described in chapter 8, weighting in chapter 9, sampling errors in chapter 10, and non-sampling errors in chapter 11. A brief conclusion is included as chapter 12. Appendices present achieved sampling fractions and the text of the sampling manual. (MNS)