In the domain of public health, this flexible and inclusive approach offers particular advantages, because there are divergent (and strongly held) views regarding what is 17 Owen & Jorm 2002 : 8. 18 NPHP 1998 , NHPC 2004 , AIHW 2004b . 19 AIHW 2004c In practice, most classifications of complex domains are multi-dimensional, either implicitly so, or explicitly constructed as such. An example in the health field is the International Classification of Diseases (WHO 1992-94) , although the relationships among the dimensions are not all set out overtly.