Based on 64 definitions of critical thinking in the recent study, it can be concluded that scholars take judgment, argument, questioning, information processing, problem solving, meta-cognition, skill and disposition as the nature of critical thinking. Scholar's disciplinary background directly affect their opinions of critical thinking, interdisciplinary research should be paid more attention to promote the development of critical thinking.

Proportional stratified sampling method is a frequently-used method in sample analysis. During the process of stratified sampling, the proportional stratified sampling and disproportionate stratified sampling methods adopted by us can improve representativeness of the sample and strengthen certainty of the estimated value of the population quantity index. Besides, it is also able to effectively avoid the phenomenon of centering on some characteristics or omitting some characteristics during simple random sampling. However, proportional stratified sampling method is not suitable for all samples, and different samples should be treated separately. By taking the proportional stratified sample of test scores gained by students of Hezhe nationality according to mother's education degree as an example, this paper provides beneficial references for research on individual aesthetic taste generation of Hezhe nationality.