Because this topic is beyond the scope of this article, we
refer the reader to the many outstanding books and articles
on statistical analysis (Cobb 1998; Cox and Reid 2000;
Dean and Voss 1999; Festing and Altman 2002; Lemons et
al. 1997; Pickvance 2001; Wasserman and Kutner 1985;
Wilson and Natale 2001; Wu and Hamada 2000).