This entry-level text offers clear and concise guidelines on how to select, construct, interpret, and evaluate count data. Written for researchers with little or no background in advanced statistics, the book presents treatments of all major models using numerous tables, insets, and detailed...

The rootogram is a graphical tool associated with the work of J. W. Tukey that was originally used for assessing goodness of t of univariate distributions. Here we show that rootograms are also useful for diagnosing and treating issues such as overdispersion and/or excess zeros in regression...

Die Arbeit umfaßt die Darstellung und Anwendung von Regressionsmodellen für Zähldaten, deren abhängige Variable nur nichtnegative ganzzahlige Werte annehmen kann. Die Spezifikationen des Poisson- und des NegBin 2-Modells mit den zugehörigen Schätzverfahren und Beurteilungskriterien werden...

Background: Dental services differ from other health services in several dimensions. One important difference is that a substantial share of costs of dental services ? especially those beyond routine dental treatment - are paid directly by the patient out-of-pocket. Objectives: We analyze the...