aspg-21-2868-1791475991 20261008161311 American Scientific Publishing Group admin@americaspg.com American Scientific Publishing Group International Journal of Neutrosophic Science IJNS 2692-6148 2690-6805 2024 24 4 Lejo J. Manavalan Department of Mathematics, Little Flower College-680103, Guruvayoor, India. Sadeq Damrah Department of Mathematics and Physics, College of Engineering, Australian University, West Mishref, Safat 13015, Kuwait. Mutaz M. Abbas Ali Zayed Military College, Department of General Science, UAE. Abdallah Al-Husban Department of Mathematics, Faculty of Science and Technology, Irbid National University, P.O. Box: 2600 Irbid, Jordan M. Palanikumar Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu 602105, India We describe certain operations and present the theory of the Type-I extension Diophantine neutrosophic interval valued soft set. Additionally, we go over an algorithm that uses the Type-I soft set model to address the decision-making problem. We present a similarity measure between two Type-I extension Diophantine neutrosophic interval valued soft sets and talk about how it might be used in practical applications. A few exemplary cases are provided to demonstrate their practical application in solving uncertain problems. 2024 151 164 2868 https://creativecommons.org/licenses/by/4.0/ 10.54216/IJNS.240411 https://www.americaspg.com/journal/21/article/2868 https://www.americaspg.com/storage/81717605641.pdf