Pew Research Center designed this study to assess the current state of online survey sampling methods – both probability-based and opt-in – and determine their accuracy on general population estimates ...

A growing share of polling is conducted with online opt-in samples. 1 This trend has raised some concern within the industry because, while low participation rates pose a challenge for all surveys, ...

Particle size distribution (PSD) analysis is a cornerstone of soil science, providing essential insights into soil structure, fertility and its response to environmental change. This analytical field ...

Power analyses and sample size calculations are important parts of many research projects. Often, before data are even collected, it is necessary to calculate and justify the required sample size for ...

Bibliometric analysis is crucial for evaluating scientific publications, traditionally relying on metrics like citation count ...