This study examines the relationship between students’ performance on mock examinations and their outcomes on subsequent real examinations. The main research question is: To what degree do mock test scores forecast performance on the actual exams, and does the time interval between the mock and real tests affect this predictive relationship? To address this question, the study analyzes a dataset consisting of paired mock and real exam results, including the dates of each assessment, using a quantitative correlational design. Statistical methods include Pearson correlation analysis to measure the strength of association and linear regression modeling to evaluate the predictive validity of mock test performance. The analysis additionally considers time interval effects to examine if the number of days between mock and real exams influences the predictive relationship. Building on the theoretical foundation that practice assessments can support readiness, this research also considers the underlying mechanisms that may strengthen or weaken the predictive link between mock and real examinations. Previous research indicates that the predictive validity of assessments is influenced by contextual variables, including familiarity with the test. Factors such as understanding the test format—which has been shown to impact the reliability and accuracy of assessment results—and cognitive load, which interacts with task complexity and testing environment to affect performance, are conceptually integrated to inform the interpretation of quantitative findings (Reeve et al., 2009; Pengelley et al., 2023). The role of formative feedback is also examined, as systematic reviews and empirical studies indicate that timely, specific feedback enhances academic performance, self-regulation, and understanding, thereby potentially strengthening the predictive value of mock examinations (Hattie and Timperley, 2007; Solis Trujillo et al., 2025; Morris et al., 2021; Sirianansopa, 2024). By integrating temporal aspects with performance metrics, the study aims to determine not only whether mock exams are good predictors but also under what conditions their predictive power is maximized. Results show that mock test scores are moderately to strongly positively correlated with real exam performance, supporting their use as diagnostic tools for assessing exam readiness. They also suggest that shorter intervals between mock and real tests yield greater predictive validity because they reduce opportunities for skill decay or instructional exposure. Ultimately, the study adds to assessment research by offering empirical evidence on the reliability and temporal sensitivity of mock examinations as predictors of real exam outcomes. These findings could be useful for educators, test designers, and institutions aiming to optimize student preparation and assessment schedules.