Abstract: On the basis of the judgement matrix of gross errors judgement equation and the function formulation of correlation coefficient between two testing values, this paper proves that both the mathematical models, in fact, are equivalent. The results of a familiar example which gross errors in the observations can not be identified based on judgement matrix are appeared to be exactly the same as that correlation coefficients between their testing values are equal to 1. Furthermore, the gross errors detectability and identifiability of observations analyzed by the judgement matrix would be more convenient and simple than by the method based correlation coefficient.