CHAPTER 3 DATA COLLECTION AND ANALYSIS 1.5 Accuracy and Limitations The majority of States that responded to the questionnaire had difficulties in providing comprehensive, up-to-date and disaggregated data on the number of children in various situations of detention. Administrative records are particularly limited in the context of migration, institutions, national security and armed conflict. Despite the fact that, through the Global Study questionnaire, we managed to collect data from all continents, the response rate varied across the regions. Most of the countries from Europe (93% of countries), Oceania (71%) and Americas (54%) submitted responses to the questionnaires. For Africa, the response rate amounted to 50% whilst in Asia it was significantly lower (42%). During the data cleaning processes, it turned out that the Asian States often reported incomplete figures which, considering the large population of the continent, significantly hindered further statistical analysis. For this reason, future research aimed at verifying these estimates should first focus on the number of children deprived of liberty in Asia, in particular South-Eastern Asia. Another issue that should be taken up by academia is the improvement of the mathematical model constructed during the Global Study by including variables, which can contribute to more accurate estimates, in particular related to the ethnic diversity and the prevalence of discrimination against minority groups. Further developments of statistical tools and methods are planned in future steps, aiming at designing a dedicated index measuring the level of respect for the freedom of the child (Child Freedom Index). 42