Two-phase Sampling vs. Multistage Sampling | Applications of Two-Phase Sampling | Replicate Variance Estimation with the 'svrep' Package | Overview of the Generalized Bootstrap | Creating Example Data | Describing the Two-phase Survey Design | Creating Generalized Bootstrap Replicates | Create Replicates Using Fay's Generalized Replication Method | Calibrating Second-phase Weights to First-phase Estimates | Preliminaries | Option 1: Calibrate to a set of estimates and their variance-covariance matrix | Option 2: Calibrate to independently-generated first-phase replicates | Ratio Estimation | Design-based Estimators for Two-phase Sampling | Notation | Notation for Samples and Sample Size | Notation for Probabilities and Weights | The Double Expansion Estimator | Variance of the Double Expansion Estimator | Estimating the Variance of the Double Expansion Estimator | Estimating the second-phase variance component | Estimating the first-phase variance component | Combining the two estimated variance components | Calibration Estimators | Variance of the Calibration Estimator | Replication Variance Estimation | Ensuring the Variance Estimator is Positive Semidefinite | Usage with the Generalized Bootstrap | Helper Functions for Ensuring an Estimator is Positive Semidefinite | References

Choosing a Bootstrap Method | Basic Bootstrap Methods | Implementation | Extracting Bootstrap Replicate Weights | Generalized Survey Bootstrap | Statistical Background | Details and Notation for the Generalized Survey Bootstrap Method | Quadratic Forms | Forming Adjustment Factors | Adjusting Generalized Survey Bootstrap Replicates to Avoid Negative Weights | Option 1: Convert an existing design to a generalized bootstrap design | Option 2: Create the quadratic form matrix and then use it to create bootstrap weights | Choosing the Number of Bootstrap Replicates | General Strategy | Measuring and Estimating Simulation Error | The Bootstrap vs. Other Replication Methods | References

Creating initial replicate weights | Redistributing weight from nonrespondents to respondents | Conducting weighting class adjustments | Propensity cell adjustment | Saving the final weights to a data file | Statistical background | Recommended Reading

Sample-based Calibration: An Introduction | Functions for Implementing Sample-Based Calibration | An Example Using a Vaccination Survey | Raking to estimated control totals | Post-stratification | Reproducibility | References