The results of a study undertaken at ITS Leeds in which simulated data is used to investigate the circumstances in which person-specific models could be useful are reported. By varying the assumptions underlying simulated behaviour, it was possible to represent a range of circumstances and to investigate the success of person-specific models in each case. Some areas for further research are identified. An important step in the investigation is the specification of appropriate ways to measure the success of models in reproducing the simulation assumptions and two separate measures have been defined and applied. The results indicate that in most circumstances person-specific models are not as successful as models based on pooled data, but when inter-personal variation is high, in ways that are described in the paper, person-specific models might indeed be useful. Thus in extreme cases it may be useful to investigate person-specific models as an intermediate step to developing a population model. The paper will be of value to SP researchers in developing methodology by indicating the limits of applicability of simple analysis methods and how to proceed when those limits are passed. The new aspects of this work are that it goes beyond the previous studies in terms of the realism of the error structures considered, therefore giving better insight into the true extent of applicability of person-specific modelling. For the covering abstract see ITRD E124693.
Abstract