本文之目的在於利用，當估計模型假設錯誤時，Bartlett的第二等式不正確的性質，來提出一個估計具有過離散性的個數資料之過離散係數的方法。再根據Presnell與Boos(2004)在附錄所提出的方法來估計過離散係數估計量的變異數，並探討估計方法的有效性。 論文中提出一個不需知道正確模型下估計過離散係數之方法，適用於對數迴歸模型或其他合理的迴歸模型。 This thesis provides a method for estimating the over-dispersion count data. And this method adopts the poisson distribution as the working model. The violation of the Bartlett’s second identity is then made use of to give rise to a useful formula for the estimation of the over-dispersion. This new means is applicable for any sensible link function that relates the response probabilities to the variates.
