This repository contains the source code supporting the research paper "Intervention Strategies in Expressed-Private Opinion Dynamics" (Kamińska B., Jędrzejewski A., Sznajd-Weron K.). It provides a dual-methodology framework to investigate how external fields (such as information campaigns or institutional policies) influence both the privately held beliefs and publicly expressed opinions of individuals: Monte Carlo Simulations (Julia): Scripts used to run microscopic, agent-based simulations to observe emergent macroscopic behaviors, consensus states, and phase transitions. Analytical Calculations (MATLAB): Scripts used to solve numerically equations within the mean-field approximation, facilitating the study of steady-states. For full theoretical details, parameter configurations, and a comprehensive analysis of the results, please refer to the main paper.