: error terms of the i and j observations respectively, This assumption is formally expressed as:Į: the expected value of all pair-wise products of error terms, Most regression methods that are used in crash modeling assume that the error terms are independent from one another, and they are uncorrelated. Temporal autocorrelation is closely related to the correlation coefficient between two or more varia- bles, except that in this case we do not deal with variables X and Y, but with lagged values of the same variable. serial correlation) is a special case of correlation, and refers not to the relationship between two or more variables, but to the relationship between successive values of the same variable.
