Evaluation of the Annif automatic indexing system in information science journal articles

Authors

DOI:

https://doi.org/10.5007/1518-2924.2026.e109644

Keywords:

Annif, Machine learning, Automatic indexing, Digital repositories, Brazilian Thesaurus of Information Science

Abstract

Objective: This study evaluates the performance of the Annif automatic indexing tool in assigning descriptors to scientific articles within the field of Information Science.

Methods: The research adopted an empirical and exploratory approach. It used a corpus composed of 60 articles written in Portuguese and previously indexed manually with the Brazilian Thesaurus of Information Science (TBCI). The corpus was divided into two subsets: 30 articles were used for training and 30 for testing. Annif was configured with the MLLM backend and compared with the terms assigned through intellectual indexing using the metrics of Precision, Recall, F1-score, and Consistency. A qualitative analysis of the generated terms was also conducted.

Results: The system demonstrated moderate performance, achieving a Precision of 49.52%, Recall of 50.1%, F1-score of 49.23%, and Consistency of 31.63%.

Conclusions: It is concluded that Annif is a viable tool for supporting semi-automatic indexing workflows, provided that its suggestions are validated by human indexers.

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Author Biographies

Remi Correia Lapa, Universidade Federal de Pernambuco

PhD candidate in the Graduate Program in Information Science at the Federal University of Pernambuco. Master's degree from the Graduate Program in Information Science at the Federal University of Pernambuco. Bachelor's degree in Library Science from the Federal University of Pernambuco (2011).

Renato Fernandes Correa, Universidade Federal de Pernambuco

He holds a Bachelor's degree in Computer Science (2000) from the Federal University of Viçosa, a Master's degree in Computer Science (2002), and a Ph.D. in Computer Science (2008) from the Federal University of Pernambuco. He completed a Postdoctoral Fellowship in Information Science (2023) at the Faculty of Philosophy and Sciences, São Paulo State University (UNESP), Marília campus. He is currently an Associate Professor at the Federal University of Pernambuco, affiliated with the Department of Information Science and the Graduate Program in Information Science at UFPE. His research interests lie in the fields of Information Science and Computer Science, with an emphasis on Information Retrieval Systems. He works primarily on the following topics: automatic indexing, text categorization, text mining, and information retrieval.

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Published

2026-07-29

How to Cite

LAPA, Remi Correia; CORREA, Renato Fernandes. Evaluation of the Annif automatic indexing system in information science journal articles. Encontros Bibli: electronic journal of library science, archival science and information science, Florianópolis/SC, Brasil, v. 31, p. 1–26, 2026. DOI: 10.5007/1518-2924.2026.e109644. Disponível em: https://periodicos.ufsc.br/index.php/eb/article/view/109644. Acesso em: 2 aug. 2026.