A very flexible hybrid censoring scheme and its Fisher information

Various hybrid censoring schemes, which are mixtures of Type I and Type II censoring schemes, have been suggested for flexibility in termination time and efficiency level. In this paper, we propose a general hybrid censoring scheme to be a censoring scheme with Type I or Type II bounds which provides more flexible termination time and efficiency level. The Type I hybrid censoring scheme can be interpreted as a Type I censoring scheme with a Type II upper bound, while the generalized Type I hybrid censoring can be interpreted as a Type I censoring scheme with Type II lower and upper bounds. The bounds involved in the termination can also be a hybrid. We then show that the unified hybrid censoring scheme of Balakrishnan et al. [Exact likelihood inference based on an unified hybrid censored sample from the exponential distribution, J. Statist. Comput. Simul. 78 (2008), pp. 475–488] is a special case of the general hybrid censoring scheme. Finally, we discuss several new hybrid censoring schemes and evaluate the Fisher information contained in them.