In a previous paper in this journal (Cook R, Evett IW, Jackson G, Jone
s PJ and Lambert JA. A model for case assessment and interpretation. S
cience & Justice 1998; 38: 151-156), the authors described a model for
case assessment and interpretation. An essential element of the model
, indeed of any interpretation, is that of framing a pair of propositi
ons to weigh against each other. It is one of the functions of the sci
entist to determine, in the light of the evidence that is found and of
the circumstances of the case as they appear at the time, the pair of
propositions that can realistically be addressed. It is helpful to co
nsider a broadly-defined ''hierarchy of propositions': In general, the
higher the level of the propositions, the greater the assistance that
will be given to the court but, of course, the scientist may not stra
y outside the bounds of his/her expertise nor, indeed, into the realms
of advocacy. This paper, a continuation of the first, discusses the h
ierarchy of propositions by means of case examples.