In this study I aim to investigate the validity and reliability of three newly developed measures for the central constructs to Schema Theory, early maladaptive schemas (EMSs), maladaptive coping styles (MCSs), and schema modes (SMs). These are the Young Schema Questionnaire-4 (YSQ-4), the Schema Coping Inventory-Revised (SCI-R), and the Schema Mode Inventory-3 Short Version (SMI-3-S). The revision of the instruments builds on prior research, incorporating new schemas and modes. This study aims to confirm the factorial validity, internal reliability, and known-groups validity of these instruments. Additionally, I aim to examine whether coping mediates the relationship between the seven newly added schemas and their corresponding modes. Data is collected internationally from clinical and non-clinical populations, with at least 772 participants required. The study employs confirmatory factor analysis and (Bayesian) latent mediation analysis to test theoretical assumptions. Findings will contribute to refining schema theory and enhancing clinical assessment tools.