Understanding TSS

Understanding the score used in selective-entry testing

Official TSS is not just a percentage. Selective Path provides an internal estimate that transforms four section results onto a 0-400 readiness scale for coaching use.

Why TSS exists

Because raw scores alone can be misleading.

Official testing bodies can equate scores using live cohort and paper-difficulty data. Selective Path does not have that official data, so its estimate uses fixed, published reference parameters instead.

In plain English: use the Selective Path estimate to compare performance across complete mocks and identify direction of travel, not as an official cohort rank.

How the 0-400 scale works

How Selective Path creates an estimated score from the four assessed areas.

1. Standardization

Raw marks are converted to a 0-100 scale for Reading, Writing, Quantitative, and Abstract so each pillar can be compared more fairly.

2. Four-pillar total

Those four standardised pillar scores are then added together, creating one TSS estimate out of 400.

3. Real-world meaning

A four-pillar estimate is more useful for coaching than one raw paper percentage because it exposes uneven performance across the complete mock.

A simple way to think about bell curves

No maths degree required.

Most students cluster around the middle. A smaller number sit well above that middle, and a smaller number sit below it. That curved distribution is what people mean by a bell curve.

When people talk about standard deviation, they simply mean how far from the middle a score sits. In the Selective Path model, a higher estimate means stronger performance against the fixed internal reference, not a confirmed position in the live applicant cohort.

A 245 score is shown as a historical Perth Modern reference point. Actual selection scores vary by year, program, applicant cohort, and official equating.

Historical Planning References

Historical figures to compare cautiously with a full-mock Selective Path estimate.

Perth Modern School
245+
Willetton Senior High School
228+
Shenton College
225+
Rossmoyne Senior High School
220+
Other Selective Streams
Typical range 210-215
212+

Illustrative historical reference points only. Check current entry information with the WA Department of Education before making school decisions. Selection scores vary annually with places, preferences, and cohort performance. These figures do not predict admission.

What parents should do with this

Use the estimate to guide preparation, not to predict admission.

  • 1. Use practice accuracy to measure knowledge.
  • 2. Use full-mock Selective Path estimates to track readiness under timed conditions.
  • 3. Compare both together to spot stamina, timing, or pressure issues.