The present study aims to investigate the use of evaluative language in the conclusion sections of research articles across four disciplines: Sociology, Law, Philosophy, and Medicine. The research is theoretically grounded in Appraisal Theory and van Dijk’s framework of Critical Discourse Analysis. Employing a mixed-method approach, both qualitative and quantitative analyses were conducted on 45 conclusion sections from articles published in reputable journals within these disciplines. The study examined the distribution of appraisal resources, including attitude (affect, judgment, appreciation), graduation (force and focus), and engagement (monoglossic and heteroglossic strategies). The findings revealed that in the humanities (Sociology, Law, and Philosophy), judgment and appreciation resources occur more frequently than in Medicine, and evaluative language in these fields is primarily used to critique institutions, reinterpret socio-political concepts, and promote social justice. In contrast, in Medicine, evaluative language mainly serves to reinforce the credibility of research methods, propose future studies, and maintain scientific objectivity. Furthermore, engagement in the humanities is characterized by heteroglossic strategies and references to diverse viewpoints, whereas in Medicine, it tends to be monoglossic and oriented toward scientific certainty. Discourse analysis of these data also indicates that the language of conclusions reflects the underlying structures of power, knowledge, and legitimacy in each discipline’s discourse. By highlighting the intersection of language and ideology, this study demonstrates that analyzing evaluative language can provide critical insights into the role of scientific discourse in knowledge policymaking and higher education.