With the aim of identifying and developing gifted students, providing them with assistance in choosing a profession and involving them in scientific research and research activities, the National Center “Junior Academy of Sciences of Ukraine” has initiated and annually holds a number of All-Ukrainian competitions of creative and intellectual direction: “Junior Erudite”, “Junior Researcher”, “Future of Ukraine”, “Ecoview” and many others. Among them, the most popular and representative in terms of the composition of its participants is the “Contest-presentation of scientific research projects”. The competition takes place in several stages, about 100,000 high school students from all over Ukraine take part in it, of which more than 1,000 of the best make it to the finals. The rules of the competition provide that a jury is created for each scientific section (of which there are 65), in which the corresponding stage of the competition is held. The members of the jury independently evaluate the research works of schoolchildren. Winners are determined in each scientific section separately by the sum of points scored by participants in all sections of the program. The final result (rating score) of each participant is calculated taking into account the weight of each component of the factor-criterion model, according to which the contestants’ achievements are evaluated, that is, the participants (alternatives) are actually ranked according to a set of indicators of different importance, which have a hierarchical structure. In order to ensure the access of the jury members to all the materials of scientific and research achievements of the contestants, as well as to carry out their effective evaluation and calculation of the final results, the information and analytical platform (IAP) POLYHEDRON-Competition was created.This article talks about the created computer system – an information and analytical platform that ensures the effective work of experts (jury members) in reviewing and evaluating scientific research materials submitted for defense by participants of intellectual contests. The system is deployed on the basis of an interactive document, which is a variant of the ontology-controlled system, and its work is illustrated on the example of the contest-presentation of scientific research projects.