In the circumstances of digital transformation of the state and society, the indicative approach to analyzing and governing digitalization finds active usage. However, the characteristics of relevant data cause methodological problems, including statistical duplication. The article considers various methods for constructing composite digitalization indices based on secondary aggregation of principal components in order to overcome duplication. It is hypothesized that there is no single best method for secondary aggregation, and that the preference of methods depends on the indicative evaluation tasks being addressed.  The lack of scientific consensus on the best aggregation method for calculating composite indices supports this proposition. Multiple widespread aggregation methods are also described. To consider the hypothesis, two potential secondary aggregation methods, alongside the option to eschew secondary aggregation, are studied. Their advantages are analyzed using common tasks of rating and analysing the strengths and weaknesses of facilities as an example. The data for analysis include principal components extracted from 21 digitalization indicators for years 2014 and 2016. Correlation analysis of their secondary aggregation’s results and country rating comparison show that different analysed methods are suitable for different tasks. This is due to the correspondence of the methods’ properties to the requirements imposed by the tasks being solved. The practical applicability of the discussed methodologies for analysing digitalization is demonstrated by the example of the Russian Federation. The study confirmed the need to consider the index construction methods’ characteristics to select the methods most appropriate to the tasks being solved. The obtained results can serve as the basis for developing a classification of requirements posed by indicative evaluation tasks, which will also contribute to systematization of aggregation methods, which has practical usefulness within the indicative approach.