Choice modelling is an area of growing popularity as many researchers and consultants seek to find better ways to explain the choices made by individuals, households and firms in many application contexts such as transportation, health services, environmental science, marketing, finance, economics, tourism, vacationing, education and employment. Choice modelling as a field began as long ago as 1927 but it was the research in the 1960s and 1970s that cemented the field as a dominant one for studying choice.