Never mind the Data – Feel the Model*

The rapid development of choice modelling procedures, especially using Stated Preference data, over the past twenty years, has created an opportunity for an imbalance between the models and the data used for construction of the models. This paper examines this imbalance and stresses the need for more attention to be paid to the needs of the respondent when collecting data for choice modelling. Drawing on the classic ideas of Alonso on the sources of error in modelling studies, the paper highlights the fact that the sophistication of the models and the data need to be commensurate. The paper gives some contrasting examples of studies in which sophisticated analysis has not been supported by equally sophisticated data collection, compared to studies where the emphasis has been placed on respondent-friendly designs without compromising the analytical outputs of the study. A major conclusion to be drawn from this paper is the absolute need to pilot test SP questions that could possibly be seen as being difficult for respondents to comprehend and answer. * with due apologies to the British comedy series "Never Mind the Quality Feel the Width", screened on ITV between 1967 and 1971, in which the differences in perspective between two London tailors are chronicled and analysed.