Aegis School Excellence Index Methodology

What the Aegis Index Measures

The Aegis School Excellence Index is a 1 to 10 rating produced for every public school in our coverage area. The score is built only from objective, publicly reported data published by the California Department of Education (CDE). Each school's underlying components and the final score are recalculated annually as new CDE data is released.

The methodology is intentionally simple to read and to audit: every input is a published CDE number, every weight is documented below, and every school's score can be reproduced from those inputs. The only adjustment is a documented one. When CDE withholds a school's Environment inputs, the Environment component is shown as N/A and its weight is redistributed across the remaining components for that school. No value is ever estimated, modeled, or filled in. Where a number is withheld by CDE it is shown as N/A, never as a substitute figure.

California Department of Education (CDE) Source Files

The index reads only the following CDE downloadable files. Each is matched to a school by its 14-digit County-District-School (CDS) code, and only the school-level, all-students (Total) row of each file is used. No demographic subgroup row is read.

• CAASPP / Smarter Balanced research file (2024-25): ELA and Math proficiency, the four ELA and three Math area subclaims, and the achievement-level distribution, by school. Year-over-year change against the 2023-24 CAASPP file produces the Growth component.
• CDE Suspension Rate file (2024-25): school-level total suspension rate.
• CDE Chronic Absenteeism file (2024-25): school-level chronic absenteeism rate.
• CDE Adjusted Cohort Graduation Rate and Outcome file (2024-25): regular high-school graduation rate and the rate meeting UC/CSU (A-G) requirements.
• CDE College-Going Rate file, 12-month (2022-23, the most recent published cycle): total college-going rate for high-school completers.
• CDE Public Schools Directory / CAASPP entities: school metadata, type, district, and ZIP for mapping schools to cities.

Data vintage: proficiency, growth, environment, graduation, and A-G reflect the 2024-25 school year. College-going reflects the 2022-23 cohort, the newest 12-month rate CDE publishes, and is labeled with that year wherever it appears.

Current data cycle

2024-2025 school year (college-going: 2022-2023)

Last full data refresh

June 2026

Next expected CDE release

Fall 2026 (2025-2026 school year)

Three Scored Components

Every school, K-8 and high school alike, is scored on the same three components: Proficiency, Growth, and Environment. Each is a real CDE measure. The two tiers use slightly different weights because they carry forward the historical balance between the components; the College Readiness component that high schools once carried has been removed from scoring (see College and Career Outcomes below).

High Schools

K-8 Schools

Side-by-Side Weight Comparison

Environment is computed only from two real CDE rates, the school-level total suspension rate and the chronic absenteeism rate; lower rates produce a higher Environment score. Where CDE withholds both rates for a school, Environment is shown as N/A and its weight is redistributed across Proficiency and Growth for that school. It is never inherited from a district average, modeled, or set to zero.

College and Career Outcomes (displayed, not scored)

High-school pages also display three real CDE outcomes: the graduation rate and the rate meeting UC/CSU (A-G) requirements from the Adjusted Cohort Graduation Outcome file, and the 12-month college-going rate (2022-23). These are shown for context beside the rating; they are not part of the scored composite. Where CDE suppresses a value, or for K-8 schools where these cohort measures do not apply, the figure is shown as N/A.

Modified Decile Mapping

After the weighted composite is computed, each school is assigned a 1 to 10 rating. The top three bands are set at fixed raw-score thresholds that Aegis calibrates and publishes: a rating of 10 requires a composite raw score of 69.0 or higher, a 9 requires 64.0 or higher, and an 8 requires 58.0 or higher. The remaining bands, 7 down to 1, are percentile-based: each school is ranked within our service-area pool and mapped to a rating using fixed percentile cutoffs. The pool is the set of public schools we cover across Santa Clara County and the adjacent service-area communities (Fremont, Redwood City, Hollister, and Santa Cruz). Ranking is relative to this regional pool, not a statewide distribution. These thresholds and cutoffs are a deliberate Aegis calibration, fixed and published so any school's rating can be checked against its composite score and its rank.

How We Audit Each Cycle

Every rating release runs through a four-step validation:

1. Source reconciliation. Each input is reconciled back to the original CDE file. Mismatches block the release.
2. Inversion check. If a school's rating moves against its raw test data without a documented Growth reason, the case is flagged for manual review before publication.
3. Distribution audit. The 1 to 10 distribution is verified against the fixed rating cutoffs across the service-area pool.
4. Drift vs Last Year. Schools whose rating moves more than three points without a CDE-side explanation are reviewed before the new rating goes live.

What Aegis Ratings Are Not

• Ratings are educational information only. They do not guarantee enrollment, school assignment, or attendance area.
• Ratings are not appraisals or property valuations. Aegis does not connect a property to a specific school.
• School district boundaries cross city lines and change over time. Always confirm enrollment boundaries directly with the district responsible for your address.
• Charter, magnet, and small-cohort schools are rated when CDE publishes sufficient public data; redacted cells are documented and inherited from the district mean rather than zeroed.
• Private schools are not rated because CDE does not require them to report on the same datasets.

Methodology and Disclaimer

The Aegis School Excellence Index is operated under the California Real Estate Agency rules and the federal Fair Housing Act. School ratings are educational information only and are not used to steer buyers toward or away from any neighborhood.

Aegis Luxury Real Estate complies with all federal, state, and local fair housing laws. We do not discriminate on the basis of race, color, religion, sex, handicap, familial status, national origin, sexual orientation, gender identity, source of income, or any other protected class.