ISA (International Schools’ Assessment): The Complete Guide for Parents at Singapore International Schools

The ISA (International Schools' Assessment) is a suite of online tests developed by the Australian Council for Educational Research (ACER) specifically for international schools. Launched in 2002, it now serves around 60,000 students from hundreds of schools worldwide each year.

The ISA is built on the frameworks used by PISA (Programme for International Student Assessment), the OECD's influential assessment of 15-year-olds. However, the ISA is not part of PISA and is not endorsed by the OECD. It extends the PISA philosophy to Grades 3–10, testing how well students can apply knowledge to real-world situations rather than reproduce curriculum-specific content.

The ISA covers four assessment areas: Mathematical Literacy, Reading, Writing (Narrative and Expository), and Scientific Literacy. All tests are delivered online and administered by classroom teachers within scheduled testing windows.

Several prominent Singapore international schools participate in the ISA. The following are confirmed participants based on published ACER data:

Other participating Singapore schools:

GEMS World Academy, Hillside World Academy, Invictus International School, ISS International School, Middleton International School, NPS International School, One World International School, Dynamic World Montessori School, Sir Manasseh Meyer International School

The ISA is an online assessment for all subjects across Grades 3–10. Schools choose from three administration windows: October, February, or May. Each testing session takes approximately 45 minutes to 1 hour.

Tests are administered by classroom teachers using detailed administration handbooks provided by ACER. The web-based platform works on Mac, PC, and iPad/tablet. Each student receives an individual login.

Multiple-choice questions are auto-scored. Open-ended questions are hand-marked by trained marking staff with subject expertise, using detailed marking guides with criteria and sample responses. Markers are trained and monitored for consistency.

Scale scores are used instead of raw scores. The PISA scale sets the OECD average for 15-year-olds at 500 (standard deviation 100) from the year 2000 baseline. This means a Grade 3 student and a Grade 10 student are measured on the same scale within each domain, allowing direct comparison and tracking of growth over time.

Proficiency levels describe what students can do at each score range. Mathematical Literacy has 10 levels across 4 content scales. Reading has 10 levels across 3 aspects. Scientific Literacy has 9 levels across 3 competencies. Writing has 10 levels for Narrative and 9 for Exposition.

The individual student report is the most important document parents receive. Below are sample reports for Mathematical Literacy and Reading, using the same scale shown earlier in the Marking section.

Each scale lists nine proficiency levels along the vertical axis, from foundational skills at the bottom to advanced reasoning at the top. The numbers on the left (200, 300, 400, ...) are the same scale scores explained earlier in the Marking section.

The inner shaded band (middle 50%) shows where half of all Grade 7 students in the ISA Reference Norm sit. The outer band (middle 90%) shows where almost all Grade 7 students fall. A child whose score lands above the inner band is performing above the grade median; below it, there is room for growth.

Scoring methodology:

• Scale scores (not raw scores) enable comparison across years and grade levels
• Proficiency levels: Math has 10 levels across 4 content scales; Reading has 10 levels across 3 aspects
• Internal consistency reliability: 0.78–0.88 across all domains
• Calibration: Item Response Theory (IRT) places students on the scale

Schools receive multiple report types: Individual Student Reports, Class Reports, School Reports, National Comparison Reports, Interactive Diagnostic Reports, and Interactive Tracking Reports.

Schools use this data for benchmarking against the international norm, diagnostic analysis to identify areas of strength and weakness at class and school level, tracking progress over multiple years, and comparing with PISA country data for Grades 8–10 students.

Help your child prepare by trying our free ISA sample questions. The tool includes official ACER sample materials for Mathematical Literacy and Reading, with instant feedback on multiple-choice questions and model answers for open-ended questions.