that maximum likelihood estimates of k can be biased upward by small sample size or under - reporting of zero - class events ,
Estimation from outbreak datasets does not increase the bias of k estimates ,
Results show that maximum likelihood estimates of k can be biased upward by small sample size or under - reporting of zero - class events , but are not biased downward by any of the factors considered .
Estimation from outbreak datasets does not increase the bias of k estimates , but can add significant upward bias to estimates of the mean .