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.
The region is regularly hit by earthquakes. The Indian Ocean tsunami of 2004 killed some 250,000 people around the region. The US Geological Survey (USGS), which documents quakes worldwide, said the first Aceh quake was centred at a depth of 33km (20 miles), about 495km from Banda Aceh, the provincial capital.