A comparison between the hierarchical clustering methods for postgraduate students in Iraqi universities for the year 2019-2020 using the cophenetic and delta correlation coefficients

The educational sector is one of the important sectors in the world, and it is considered one of the means of community development. In addition, it is one of the means of making the country’s renaissance and development because it represents the factory of thinking minds that make change. There is no doubt that this sector is the same as any other sector. The deficit in the studied scientific planning has been prolonged, which led to its deterioration, and the problems of education remain diverse and inherited from previous time periods, where the hierarchical cluster analysis was used on postgraduate students in universities in Iraq, except for Kurdistan region, and the number of universities that were included in the study was (30) universities. In the whole of Iraq for the year 2020, when using the comparison measures the Cophenetic Correlation Coefficient (CCC) and the Coefficient Delta (DC), it was found that the Complete Linkage Method is the best among the hierarchical methods, as the value of (CCC) is 0.952061, and the value of (DC(0.1)) it is 0.288973, and in the case (DC(0.5)) it is 0.26877, then followed by Median method, Ward's method and finally Single Linage Method.