摘要:A class of density estimators based on observed incomplete data are proposed. The method is to use a conditional kernel, defined as the expectation of a given kernel for the complete data conditioning on the observed data, to construct the density estimator. We study such kernel density estimators for several commonly used incomplete data models and establish their basic asymptotic properties. Some characteristics different from the classical kernel estimators are discovered. For instance, the asymptotic results of the proposed estimator do not depend on the choice of the kernel $k(\cdot )$. Simulation study is conducted to evaluate the performance of the estimator and compared with some exising methods.