An essential component of all software inspection processes is a well-founded decision about continuing or stopping the current process. This decision should be based upon directly relevant quantitative information -the number of defects remaining in the artefact. This quantity can be estimated by the use of capture-recapture methods. Several software engineering papers have explored this topic, but the question of which capture-recapture technique is best still remains unresolved. This paper attempts to shed further light upon this question. After reviewing the relevant capture-recapture models and previous evaluations within a software engineering context, the paper proceeds to evaluate the models by using data collected from subject-based experiments on software inspection. The experiments used artefacts where the number of defects was known and hence a direct measure of the accuracy of the various capture-recapture techniques was available. The paper reports that most heterogeneity models show, in general, superior performance -especially the Jackknife estimator. However, the paper concludes that further work is required to correct the limitations of the current models if reliable estimates are to be achieved.