讲座简介: | For Neyman's design-based inference, we introduce and compare ideas and implications of two virtual random mechnisms after actual sampling practice. One is named "virtual permutation", due to professor Knottnerus, with most details presented in the monograpch "Sample Survey Theory: Some Pythagorean Perspectives". The other is proposed recently by the author, named "imaginary census", for which a key element is the imaginary census matrix, recording the exact sampling trajectory of each draw without replacement, until all population units were pretended to be sampled out. Both provide interesting supplement to Neyman's conventional framework. In particular, both provides insight into relationship of simple random sampling with and without replacement. |