This module is designed to assist researchers in developing accurate and reliable answers to questions about Head Start and the children and families who are served by the program. The module includes two topics that are central to this overall goal. The first topic focuses on sampling weights. It includes a general introduction to sampling weights (what they are, how they are created and used), followed by a description of the sampling weights included with the FACES 2014 data. The second topical module focuses on estimating variances and standard errors for complex sample designs. It begins with an introduction to the issues surrounding the estimation of variances and standard errors when the data come from a complex sample design, not a simple random sample (SRS), and identifies different methods for calculating variances and standard errors for complex designs.