AustraliaVICAltonaSt Mary's School

St Mary's School

CatholicPrimaryPrep-6
Altona, VIC 3018 · Major Cities
03 5775 2670
Students259enrolled
Ratio1:13.1student:teacher
SEIFA8/10advantage decile
Community Profile
1060
ICSEA (+60 vs avg)
SEA Top ¼21%
SEA Bottom ¼13%
SEIFA Decile8/10
Indigenous0%
LBOTE15%
St Mary's

Socio-Educational Advantage — ICSEA

ICSEA (Index of Community Socio-Educational Advantage) measures the socio-educational profile of this school's community — not the school itself. The national average is 1,000. It is calculated from parental occupation, parental education, geographic remoteness, and Indigenous enrolment proportion.

ICSEA Score1060
800 (most disadvantaged)Above average1200 (most advantaged)
SEIFA IRSD Decile
8/10
least disadvantaged areas nationally
SEIFA IRSD Score
1054
Area-level index (ABS 2021)
ICSEA: ACARA (2025). SEIFA: ABS Census 2021.

Community Composition

St Mary's School's community composition is broadly balanced across socio-educational quarters, reflecting a relatively diverse intake compared to many Australian schools.

The chart below shows the proportion of students at St Mary's School from each socio-educational advantage quarter nationally. The white reference line marks 25% — the expected value if students were distributed evenly across quarters. Deviation from 25% in any quarter indicates a skewed community intake. The school draws predominantly from the upper half.

Top quarter
-4pp below avg21%
National average: 25% in each quarter
Upper middle
+11pp above avg36%
National average: 25% in each quarter
Lower middle
+5pp above avg30%
National average: 25% in each quarter
Bottom quarter
-12pp below avg13%
National average: 25% in each quarter
Source: ACARA (2025). National average: 25% per quarter.

Why Community Composition Matters

ICSEA is not a quality ranking

ICSEA measures the community a school serves — not how well the school teaches. Two schools with identical ICSEA scores can have dramatically different teaching quality, culture, and outcomes. ICSEA is context, not verdict.

Always compare like with like

Comparing NAPLAN results between schools with different ICSEA scores is comparing communities, not schools. For meaningful comparison, look at schools within 30–40 points of each other on the ICSEA scale.

The composition shift over time

A school's community composition can shift significantly as a suburb gentrifies or a catchment area changes. A school that was below average in ICSEA a decade ago may now be serving a very different community — and vice versa.

SEIFA supplements ICSEA

SEIFA IRSD measures the geographic area around the school (from Census data). It provides a complementary view — especially useful for understanding schools in gentrifying or rapidly changing neighbourhoods where ICSEA may lag behind the on-the-ground reality.