What variables and hypotheses are associated with REALISM? (international relations?

Correlation coefficient between two variables?

• Suppose the correlation coefficient between two variables is found to be -0.19. Which of the following statements are true? A. there is a slight tendency for small values of one variable to be associated with large values of the other variable B. there can be no relationship between the variables C. a scatter plot of the points would show some downward trend D. there is a slight tendency for low values of one variable to be paired with low values of the other variable E. there is a strong negative relationship between the variables F. one variable causes a small change in the other variable G. there may be a negative linear association between the variables, though this is very weak

• Answer:

  A true if you are using the product-moment coefficient B true - there COULD be no relationship at all - just a random scatter with a pair of point lined up by chance. C true - but it would be only just noticeable - mostly the points would look like a splatter from a sneeze! D false the minus-sign shows that they are inversely related, if at all. E false - the r-value 0.19 should be squared to give you some idea of the strength of the relationship; it is then called the coefficient of determination. Here it is -0.19² = 0.0361 which shows that only 3.61% of the variation in one variable can be explained by the position of the regression line. This is very small indeed. The reference below shows the minimum critical values for the correlation coefficient, if there is to be good evidence for a relationship. You would need more than 150 scatter-points for such a low value to be taken as evidence. F false - we don't know the gradient parameter of the relationship, no matter how weak it is. In fact, the most likely explanation for the small -0.19 is that changes in one variable do not cause changes in the other. G true - there MAY be, but the evidence is against it at the moment. OK?