Open access resources: the efficiency of metadata and services

The development of open science ideas and principles has facilitated the spread of open access resources (OARs), creating a wide range of information retrieval and bibliometric capabilities for analyzing various documents, journals, authors, organizations, research areas, thanks to the increased effectiveness of metadata, the links between resources, the implementation of proprietary classification systems in OARs, and data enrichment using artificial intelligence technologies. Metadata plays a crucial role in enhancing the effectiveness of OARs, as it serves as a means of document management, ensuring their identification, systematization, visibility, search, discovery, and access control in information retrieval systems. However, unified approaches are lacking regarding 1) the representation of metadata in OARs, 2) the development of classification schemes and services for processing search results, and 3) the presentation of search fields. This exacerbates the problems often encountered when working with information resources related to metadata quality (incompleteness, inaccuracy, errors, inconsistencies, subjectivity in subjectification and systematization) and their interoperability during automatic exchange, processing, and use. The study aims to analyze the effectiveness of metadata representation in major scientific OARs and their functionality for document search and processing. To achieve this goal, the first stage involved a content analysis of 10 reviews from 2023–2025. These reviews compared major scientific OARs (Crossref, Dimensions, OpenAlex, Scilit, Semantic Scholar, The Lens, etc.) with international scientometric databases Scopus and Web of Science Core Collection in terms of metadata completeness and quality, confirming the potential of OARs as bibliographic sources for scientific information retrieval. To validate these findings, the second stage involved an analysis of metadata in four selected major scientific OARs (OpenAlex, Dimensions, The Lens, and Semantic Scholar), assessing their service functionality for conducting bibliometric research and visualizing the resulting data. Furthermore, the proprietary or adopted document classificat