I liked this article, and it nicely demonstrates the concept of âcontrolling for other variablesâ (IQ, career, income, age, etc) in order to best isolate the true relationship between just the 2 variables in question.t also should be noted that controling for other variables does only make sense when the explanatory variables are moderately correlated (collinearity). In the aforementioned example, the Product-Moment correlation between exposure and covariate is 0.50, i.e. 2.
In Indonesia, at least 3,000 of the dead were in Banda Aceh, the capital of Aceh province, and officials said the death toll was likely to rise. Communication with many coastal areas was impossible, and the extent of the damage there remained uncertain.
Several people have reportedly died in the wake of a 7.9 magnitude earthquake off the west coast of Sumatra in Indonesia. Tsunami warnings were issued in Indonesia and parts of Australia, spreading panic in some provinces of Sumatra, areas which were the worst affected by the 2004 Indian Ocean quake.