Dummy variables have been employed frequently in strategy research to capture the influence of categorical variables. However, misinterpretation of results may arise, especially when interaction ...

The most frequently used practical regression model is that in which it is supposed that the dependent variate is normal for given values of the independent variate. In this paper it is pointed out ...

A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Identifying causal relationships from observational data is not easy. Still, ...

The standard linear regression model does not apply when the effect of one explanatory variable on the dependent variable depends on the value of another explanatory variable. In this case, the ...

The purpose of this tutorial is to continue our exploration of regression by constructing linear models with two or more explanatory variables. This is an extension of Lesson 9. I will start with a ...