In this series, I previously gave an overview of the main types of study design and the techniques used to minimise biased results. Here, I describe cross-sectional studies, their uses, advantages ...

Previously in this series I have given an overview of the main types of study design and the techniques used to minimise biased results. In this article I describe more fully ecological studies ...

Vivian C. Wong, Peter M. Steiner, Thomas D. Cook, Analyzing Regression-Discontinuity Designs With Multiple Assignment Variables: A Comparative Study of Four Estimation Methods, Journal of Educational ...