What are key point in the text bellow Educational inequality occurs in multiple forms. Van de Wefhorst and Mijs (2010) discussed its existence through the inequality of educational opportunity in terms of the influence of social background on students’ t

Key Points:

**Forms of Educational Inequality**: Educational inequality manifests through disparities in opportunities and performance, largely influenced by students' social backgrounds.

**Conceptual Distinction**: There is a difference between having equal performance distribution (dispersion) in educational achievement and equal opportunities; generally, societies with equal dispersion also tend to have equal opportunities.

**TIMSS Participation and Trends**: 25 education systems participated in both the 1995 and 2015 TIMSS assessments for grade eight mathematics, with an average achievement increase of only five points over 20 years.

**Recent Gains**: For 32 education systems that participated in TIMSS in both 2011 and 2015, there was an average gain of nine score points, indicating that systems starting from a lower baseline may show larger improvements.

**Limited Information on Home Background**: The assessment data from TIMSS lacks sufficient information about family and home backgrounds, making it difficult to fully understand the variations in educational performance across different systems.

**Focus on Socioeconomic Status (SES)**: The study intends to explore the connection between socioeconomic status and educational achievement, as a way to address educational inequality.

**Upcoming Sections**: The chapter will discuss the concepts and measurement of SES, as well as existing literature on the link between family SES and student academic performance, before examining differences among education systems and trends in educational inequality over time.