Consensus-Based Automatic Group Decision-Making Method with Reliability and Subjectivity Measures Based on Sentiment Analysis Bajaña-Zajía, Johnny Trillo Vílchez, José Ramón Cabrerizo Lorite, Francisco Javier Morente-Molinera, Juan Antonio Consensus Group decision-making Natural language processing The use of informal language on social media and the sheer volume of information make it difficult for a computer system to analyse it automatically. The aim of this work is to design a new group decision-making method that applies two new consensus methods based on sentiment analysis. This method is designed for application in the analysis of texts on social media. To test the method, we will use posts from the so called social network X. The proposed model differs from previous work in this field by defining a new degree of subjectivity and a new degree of reliability associated with user opinions. This work also presents two new consensus measures, one focused on measuring the number of words classified as positive and negative and the other on analysing the percentage of occurrence of those words. Our method allows us to automatically extract preferences from the transcription of the texts used in the debate, avoiding the need for users to explicitly indicate their preferences. The application to a real case of public investment demonstrates the effectiveness of the approach in collaborative contexts that used natural language. 2025-09-15T09:52:20Z 2025-09-15T09:52:20Z 2025-08-03 journal article Bajaña-Zajía, J.; Trillo, J.R.; Cabrerizo, F.J.; Morente-Molinera, J.A. Consensus-Based Automatic Group Decision-Making Method with Reliability and Subjectivity Measures Based on Sentiment Analysis. Algorithms 2025, 18, 477. https:// doi.org/10.3390/a18080477 https://hdl.handle.net/10481/106311 10.3390/a18080477 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional MDPI