  The likelihood ratio (LR) measures the relative weight of forensic data
regarding two hypotheses. Several levels of uncertainty arise if frequentist
methods are chosen for its assessment: the assumed population model only
approximates the true one and its parameters are estimated through a database.
Moreover, it may be wise to discard part of data, especially that only
indirectly related to the hypotheses. Different reductions define different
LRs. Therefore, it is more sensible to talk about "a" LR instead of "the" LR,
and the error involved in the estimation should be quantified. Two frequentist
methods are proposed in the light of these points for the `rare type match
problem', that is when a match between the perpetrator's and the suspect's DNA
profile, never observed before in the database of reference, is to be
evaluated.
