Methodology
How We Research Every School
William Prep independently researches international schools and international-track Article 1 schools in Japan, and publishes what we find with its sources attached. This page explains how that research works, and our relationship with the schools we cover.
On Independence
William Prep also operates a bilingual tutoring and academic mentorship practice for students at international schools in Japan. Our school research is produced under an independent editorial policy from that business — we do not recommend or rank schools, and deliberately avoid "best school" or ranking formats.
Six Tiers of Sources
Sources are ranked in tiers. A lower number takes precedence, and when sources disagree we generally favour the lower tier — though we report the disagreement rather than silently picking a side.
Primary
The school's own site, fee schedules, handbooks, prospectuses
Official
MEXT, the Tokyo Metropolitan Government, prefectural boards of education
Accreditation authorities
The IB, Cambridge, WASC/CIS and similar accreditors' own registries
Reputable third party
Established media, existing school databases (treated as needing escalation)
Direct statements
Interviews or statements from school staff
William Prep analysis
Our own interpretation — never presented as fact.
How Confidence Is Labelled
Every figure and claim on a school page carries one of four labels. These describe how well-confirmed the information is — not the school's quality.
Directly confirmed against a tier 1–3 source.
Reported across sources, but not yet directly confirmed against a primary one.
Calculated by William Prep from published figures — the calculation is stated.
A deliberate, published statement that this isn't publicly confirmed.
For Schools
If you're from one of the schools we cover and something on your page needs correcting or updating, we'd welcome hearing from you — school verification is a core part of how we intend this to improve over time, not an afterthought.
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