Evaluation of the human development index (HDI) using the methods of sample theory

This paper aims to determine which of the two sample plans, i.e., a simple random sample without replacement, or a stratified sample, gives a more accurate estimate of the feature's mean. The feature that was the subject of this research is the human development index in 2018. The analysis included 189 countries globally, classified into specific categories according to the United Nations development classification. The research results showed that a more accurate estimate of the mean of the human development index was obtained by applying a stratified sampling since the mean of the human development index is close to the population mean. Also, the variance of the sample mean is lower than the value obtained by applying a simple random sampling without replacement. Therefore, it was justified to approach stratification, which indicates that in the case of conducting research, the use of a stratified sampling should be considered since it provides a more precise estimate of the mean.