This anthology summarizes trends in Norwegian students’ performance and learning conditions in mathematics and science, based on data from the TIMSS survey. The analyses show that inequalities in schools have increased, particularly related to students’ socioeconomic background, school environment, and motivation. At the same time, average performance has remained relatively stable, but the spread in achievement has grown, challenging the school’s ability to provide equitable education. School leadership emerges as a key factor. Principals with relevant education and experience are positively associated with higher student performance. In addition, teaching quality, high self-confidence, motivation, and curriculum implementation are of great importance. TIMSS data also show that effort during test situations is linked to performance. The studies in the anthology also highlight the need to strengthen students’ conceptual understanding and critical thinking, especially in algebra and interpretation of graphical representations. The anthology provides a research-based foundation for further school development and policymaking, emphasizing that schools have the capacity to promote social equity and academic progress—provided they receive the right frameworks and resources.