Hidden Gem Schools in New South Wales
We analysed 2,298 schools in New South Wales and found 95 hidden gems: NSW schools whose NAPLAN results stand well above what their community advantage (ICSEA) would predict.
Key Findings
- 95 of 2,298 New South Wales schools deliver NAPLAN results at least 20 percentile points above their community advantage (ICSEA) position in the state.
- ICSEA and NAPLAN results are closely linked across Australia (r = 0.912), so a school far above the line is doing something its intake alone does not explain.
- The highest Gem Score in New South Wales is +67, at St Hurmizd Assyrian Primary School. Its hidden gems have an average ICSEA of 988.
Frequently Asked Questions
What is a hidden gem school?
A hidden gem is a school whose NAPLAN results stand well above what their community advantage (ICSEA) would predict, judged against other schools in the same state. A school qualifies when its Gem Score, the gap between its state NAPLAN percentile and its state ICSEA percentile, is 20 or higher.
What is community advantage (ICSEA)?
ICSEA, the Index of Community Socio-Educational Advantage, describes a school's student intake. It is built mainly from parents' education and occupations, adjusted for the school's remoteness and the share of Indigenous students, with 1000 the national average. It is not a measure of income or wealth. Across the schools analysed, ICSEA and NAPLAN results move closely together, which is why results far above what ICSEA predicts stand out.
How is the Gem Score calculated?
The Gem Score equals the school's NAPLAN Index Percentile minus its ICSEA Percentile, both calculated within the same state. The NAPLAN index (0-100, 50 = national average) compares each school's results with other schools at the same year level and domain, so primary and secondary schools are measured fairly. A Gem Score of +20 or higher qualifies as a hidden gem.
Why are percentiles calculated within each state?
Each state runs its own school system, and intakes differ between states. Ranking within the state compares a school with the schools a family in that state could actually choose between.
Does a high Gem Score mean a school is good?
A high Gem Score means the school's NAPLAN results are well above what its intake would predict. It says nothing about wellbeing, programs or fit for a particular child, so use it as a starting point and read each school's full profile.
Until October 2026 this list compared schools with suburb house prices; it now compares them with community advantage (ICSEA).