Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discussion of "Impact of Frequentist and Bayesian Methods on Survey
  Sampling Practice: A Selective Appraisal" by J. N. K. Rao   This comment emphasizes the importance of model checking and model fitting
when making inferences about finite population quantities. It also suggests the
value of using unit level models when making inferences for small
subpopulations, that is, "small area" analyses [arXiv:1108.2356].

3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an