Estimating the size of a hard-to-count population is a challenging matter. In particular, when only few observations of the population to be estimated are available. The matter gets even more complex when one-inflation occurs. This situation is illustrated with the help of two examples: the size of a dice snake population in Graz (Austria) and the number of flare stars in the Pleiades. The paper discusses how one-inflation can be easily handled in likelihood approaches and also discusses how variances and confidence intervals can be obtained by means of a semi-parametric bootstrap. A Bayesian approach is mentioned as well and all approaches result in similar estimates of the hidden size of the population. Finally, a simulation study is provided which shows that the unconditional likelihood approach as well as the Bayesian approach using Jeffreys’ prior perform favorable.

估算难以计数的人口规模是一个具有挑战性的问题。特别是在只有很少的估计人口观测值可用时。当发生一次通货膨胀时，事情变得更加复杂。通过两个示例说明了这种情况：格拉茨（奥地利）的骰子蛇种群数量和and宿星中的耀斑恒星数量。本文讨论了如何在似然法中轻松处理一次通货膨胀，还讨论了如何通过半参数自举获得方差和置信区间。还提到了贝叶斯方法，所有方法都导致对人口隐性规模的相似估计。最后，