Corbett School

Corbett, OR · Grades K–12 · Charter

Portland-Vancouver-Hillsboro, OR-WA

Charter

Decoded Rank

All factors combined

1½ stars

OR statewide rating — the rank below is this school's statewide position

Bottom 30% decoded

#558 of 680

plausibly #421–641

Oregon schools

#281 · Portland-Vancouver-Hillsboro metro — Oregon side

Achievement Rank

Raw test performance

Middle 40% achievement

#407 of 680

Oregon schools

#234 · Portland-Vancouver-Hillsboro metro — Oregon side

places from achievement to Decoded Rank

Raw achievement and decoded performance are both close to expected for this school's context.

Data confidence:Medium871 students tested 9 years85% participation

Confidence is computed from sample size, year coverage, and participation rate. Higher confidence means the rank shift is stable across years and not driven by a single small cohort.

  • Tested students: total students with valid scores across all reported years.
  • Years of data: number of school years included. More years smooths year-to-year noise.
  • Participation: share of enrolled students who took the assessment. Low participation can bias scores.

What's driving this rank

Decoded Rank: #558 of 680

in Oregon schools

Raw test scores rank this school #407, but families here have higher-than-average income and educational attainment, so the expected score is also high. After accounting for context, this school performs about as predicted — the Decoded Rank is #558.

Each component below is scored on a 0–100 within-metro scale. A qualitative band summarizes where the school lands.

  • LowPerforms above what its context predictsCounts for 39% of the rank

    After accounting for income and demographics, does this school beat what the data would predict?

  • About averageStudents gain ground year over yearCounts for 33% of the rank

    Are kids at this school learning faster than typical for the metro?

  • About averageEquity within the schoolCounts for 17% of the rank

    Are students clustered at similar levels, or split between top and bottom?

  • StrongMost students were testedCounts for 11% of the rank

    Was the rank computed against a representative share of the school's students?

Show the numbersFor the methodology-curious

Each component is converted to a 0–100 within-metro percentile (100 = top of the metro). "Contribution" is the percentile-points the component adds to (or subtracts from) the metro median before the schools are re-ranked into the composite.

Per-component contributions to this school's Decoded Rank composite. Weight is the share each component carries; percentile is the school's within-metro score on that component.
ComponentWeightPercentileContribution
Performs above what its context predicts 39%13-14.4
Students gain ground year over year 33%47-0.8
Equity within the school 17%48-0.3
Most students were tested 11%85+3.9

How the Decoded Rank composite is computed

Why trust this?
  • Public data sources
  • Context-adjusted model
  • Confidence shown
  • Methodology published

This score uses state assessment data, NCES enrollment data, and Census ACS 5-year neighborhood data. The Decoded Rank adjusts for school context — student demographics, ELL/SPED service rates, and the socioeconomic profile of the surrounding tract — and shows how the school performs relative to expectation, not in absolute terms.

SchoolDecoder is one signal, not a verdict. Decoded Rank is a context-adjusted residual, not a causal claim about teaching quality. See full methodology →

Strongest Subjects (Decoded)

Decoded rank first; achievement rank in parentheses. Sorted by decoded rank, best first. Science is shown for reference only and is not part of any rank, tier, or composite.

  1. Science

    2025 proficiency27.2%meeting standard

    Tested gradeGrades 5, 8

    126 tested

    202228.6%202330.1%202432.4%202527.2%

    Shown for reference only — science is not part of any rank.

All Rankings

How this school ranks across the metro, state, and among demographic peers.

ScopeAchievementDecodedShift
OR (680 schools)#407#558
Portland-Vancouver-Hillsboro, OR-WA (345 schools)#234#281
Among similar schools (6 peers)#3#3

Resource context

School inputs, not ranking points

These fields describe the school and surrounding neighborhood. They help readers interpret the page, but this is not a dollar-by-dollar or ratio-by-ratio scorecard and the fields here are not components of the Decoded Rank.

Enrollment
1,076
Free/reduced-price lunch
36.7%
Student-teacher ratio
20.3:1
Locale
Rural, fringe
School type
Charter school
Enrollment model
Charter enrollment
Neighborhood median income
$104,503ACS tract proxy
Neighborhood poverty
7.3%ACS tract proxy
SES index
80.9
Assessment data year
2025
CCD year
2024
ACS vintage
2020-2024

High School Outcomes

Latest available data

Graduation 2025 · Coursework 2021 · AP exams 2015 · SAT/ACT 2021

HS Decoded Rank #38 of 39 among high schools in this metro

Context-adjusted

Achievement vs. demographic expectation

Bottom 15%

1 star

Achievement

Raw test performance

Bottom 15%

This is context-adjusted achievement (Alpha) — how grade 10–11 scores compare to expectations from the school's demographics. It is not the growth-based composite shown for elementary and middle schools, because a single-tested-grade high school has no consecutive-grade cohort to measure growth from.

Subject performance

Annual share of the tested high-school grade meeting or exceeding the state standard. Science is descriptive and is not included in the ELA + math HS Decoded Rank.

  1. ELA

    2025 proficiency26.3%meeting standard

    Tested gradeGrade 11

    57 tested

    201566%201676.6%201777.1%201878.7%201983.9%202265.8%202370%202449.2%202526.3%

  2. Math

    2025 proficiency19.3%meeting standard

    Tested gradeGrade 11

    57 tested

    201524.6%201653.1%201732.7%201836.5%201948.4%202237.5%202330%202422%202519.3%

  3. Science

    2025 proficiency5.2%meeting standard

    Tested gradeGrade 11

    58 tested

    202264.1%202362%202427.6%20255.2%

Proficiency over time↓ declining
  1. 201545%
  2. 201665%
  3. 201755%
  4. 201858%
  5. 201966%
  6. 202251%
  7. 202350%
  8. 202436%
  9. 202523%

Share of the tested grade (grade 10–11) meeting or exceeding standard in ELA + math, year over year. This is the school's achievement trend for the tested grade — not student growth and not the K-8 cohort-progression signal.

Graduation
91%
2025 cohort · 97% extended · 80 students in cohort
AP coursework
312
415 exam takers (2015) · 28% scored 3+
9th-grade on-track
89%
92 in cohort · SY 2024-25
Advanced options
AP · Dual credit
129 students in advanced math · CRDC 2021
SAT/ACT tested
111
CRDC 2021

Data confidence: Low— tested-student count, years of data, and participation for the high-school grades

Data limitations

  • Graduation uses state cohort data. Coursework, offerings, and SAT/ACT counts use the latest available federal CRDC extracts, which can lag current graduation data.
  • SAT/ACT data is count-only in this extract; without an enrollment denominator, we do not treat it as a participation rate.
  • HS Decoded Rank is alpha-only: it summarizes how the school's grade 10/11 test scores compare to expectations from its demographic context, ranked against other HSs in the same metro / state / rural cohort. Graduation, AP, and SAT/ACT data above are descriptive context — they are not yet blended into the composite rank. The achievement-vs-decoded quadrant below plots context-adjusted ACHIEVEMENT (alpha) against raw achievement; it is NOT the growth-based composite shown for elementary and middle schools, because a single-tested-grade high school has no consecutive-grade cohort ladder from which to build a growth signal.

Within Corbett SD 39: #1 of 1. View district

Performance Spread

How students are distributed across the four state-assessment proficiency levels — L1: below standard, L2: approaching, L3: meets (proficient), L4: exceeds. This describes the shape of results at the school, not their height.

Students at this school are typically spread across proficiency levels.

  • Level 1 — Below standard42%
  • Level 2 — Approaching standard26%
  • Level 3 — Meets standard (proficient)20%
  • Level 4 — Exceeds standard12%

Performance Spread measures how evenly students are distributed across the L1..L4 proficiency ladder, treating the levels as an ordered scale (L1=1, L2=2, L3=3, L4=4) and weighting each by its student share. A school where most students cluster at one level has a TIGHT spread; a school split between the bottom and top has a WIDE or BIMODAL spread. Bimodal fires only when BOTH tails are non-trivial AND the middle is relatively hollow (pct_L1 ≥ 15, pct_L4 ≥ 25, pct_L2 + pct_L3 ≤ 60). It describes shape — NOT how high the school's scores are. Methodology

Nearby Schools

Sorted by distance. Both rank columns shown so you can compare quickly.

SchoolRatingAchievementDecodedShiftStoryConfidence
Jemtegaard Middle School#20#1High
Columbia River Gorge Elementary School#54#10High
Washougal Special ServicesRankings coming soon
Mount Pleasant School#21#68Low
Washougal High School#9#12HSHS outcomeHS pool

Similar Schools

Schools with comparable demographics, income, and size. Both rank columns shown for direct comparison.

SchoolRatingAchievementDecodedShiftStoryConfidence
Lakeridge Middle School#55#48Medium
Lake Oswego High School#3#3HSHS outcomeHS pool
Rosemont Ridge Middle School#86#179Medium
Ida B. Wells-Barnett High School#10#21HSHS outcomeHS pool
Marshfield Senior High SchoolRanking unavailable

Historical Ranks

Year-by-year decoded and achievement ranks. Pandemic-affected years are excluded — we don't interpolate scores across the gap.

YearAchievementDecodedShift
2025#234#281
2024Excluded
2023Excluded

Note: assessment transitions (where a state changes its test) are footnoted on the methodology page; trends are not computed across breakpoints.

Trajectory

Not used in the Decoded Rank — shown for context only.

Not enough years yet

Trajectory will appear once we have two or more years of rankings for this school.

How this works: we fit a linear trend across the available years of Decoded percentile, then bucket the slope into a direction. Wide confidence intervals (uncertain trends) collapse to Holding steady. See the methodology page for thresholds.

Cohort Progression

Kids who started 3rd grade here in 2024 lost 2 proficiency points by 4th grade — declining about 9× faster than the metro median.

Based on 28 cohorts across math + ELA.

Learning rate: -4.9 proficiency points/yr (95% CI -7.2 to -2.6)

Cohort 201520162017201820192022202320242025 Slope
ELA · started 11th in 2015
G11
287
—
ELA · started 11th in 2016
G11
315
—
ELA · started 11th in 2017
G11
301
—
ELA · started 11th in 2018
G11
321
—
ELA · started 7th in 2015
G7
280
G8
269
G11
325
+12.9
ELA · started 6th in 2015
G6
230
G7
246
G8
246
+7.8
ELA · started 5th in 2015
G5
283
G6
211
G7
228
G8
249
-8.5
ELA · started 4th in 2015
G4
317
G5
263
G6
239
G7
253
G8
259
G11
292
-0.6
ELA · started 3rd in 2015
G3
245
G4
268
G5
267
G6
260
G7
260
G11
284
+3.5
ELA · started 3rd in 2016
G3
250
G4
236
G5
269
G6
248
G11
246
-0.3
ELA · started 3rd in 2017
G3
222
G4
255
G5
262
G8
238
G11
179
-7.0
ELA · started 3rd in 2018
G3
230
G4
270
G7
271
G8
202
-4.1
ELA · started 3rd in 2019
G3
231
G6
236
G7
251
G8
247
+3.7
ELA · started 5th in 2022
G5
235
G6
238
G7
240
G8
204
-9.0
ELA · started 4th in 2022
G4
227
G5
247
G6
197
G7
197
-13.9
ELA · started 3rd in 2022
G3
237
G4
277
G5
253
G6
246
+0.6
ELA · started 3rd in 2023
G3
229
G4
215
G5
233
+2.2
ELA · started 3rd in 2024
G3
202
G4
203
+0.2
ELA · started 3rd in 2025
G3
180
—
Math · started 11th in 2015
G11
191
—
Math · started 11th in 2016
G11
243
—
Math · started 11th in 2017
G11
213
—
Math · started 11th in 2018
G11
210
—
Math · started 7th in 2015
G7
273
G8
244
G11
236
-7.7
Math · started 6th in 2015
G6
227
G7
241
G8
211
-8.2
Math · started 5th in 2015
G5
250
G6
212
G7
214
G8
190
-17.8
Math · started 4th in 2015
G4
267
G5
228
G6
222
G7
247
G8
223
G11
220
-4.5
Math · started 3rd in 2015
G3
227
G4
263
G5
257
G6
244
G7
254
G11
206
-4.5
Math · started 3rd in 2016
G3
224
G4
242
G5
214
G6
204
G11
166
-8.5
Math · started 3rd in 2017
G3
223
G4
250
G5
235
G8
178
G11
160
-10.7
Math · started 3rd in 2018
G3
230
G4
257
G7
237
G8
172
-10.3
Math · started 3rd in 2019
G3
226
G6
223
G7
236
G8
207
-2.0
Math · started 5th in 2022
G5
213
G6
213
G7
233
G8
188
-5.6
Math · started 4th in 2022
G4
217
G5
215
G6
193
G7
201
-6.9
Math · started 3rd in 2022
G3
258
G4
272
G5
239
G6
212
-17.1
Math · started 3rd in 2023
G3
229
G4
238
G5
198
-15.3
Math · started 3rd in 2024
G3
212
G4
210
-2.3
Math · started 3rd in 2025
G3
202
—

How this works: we follow each grade-cohort across years through the school (3rd graders in 2023 are 4th graders in 2024, etc.) and fit a linear slope on a 100–400 proficiency-points scale built from the state assessment's four levels (L1=1, L2=2, L3=3, L4=4, weighted by student share). This is the same construction Stanford SEDA uses (edopportunity.org/methods); it's not student-level tracking — we measure the school's cohort, not individuals. See the methodology page for thresholds.

Evidence & technical detailClick to expand

School Alpha

School Alpha is the residual between actual and expected performance once school context is held constant. It is a context-adjusted estimate, not a causal claim about teaching quality. Its reliability shows up on the page as the confidence label and the rank interval, not as a standalone statistic.

SES index components

SES method
Blended SES index (ACS + FRL)
SES index value
80.9
FRL %
36.7%
ELL %
5.0% · OR ODE At-A-Glance (Ever English Learners)
SPED %
22.0% · OR ODE At-A-Glance
Tract median income (ACS 5-year)
$104,503
Tract poverty rate
7.3%
Tract % bachelor's+
42.4%

What "Decoded Rank" means

Decoded Rank converts School Alpha — the context-adjusted residual — into a parent-facing rank within the metro pool. A higher Decoded Rank than Achievement Rank means the school's raw scores understate its performance once neighborhood and school context are held constant. The reverse means raw scores overstate it. The rank is one signal, not a verdict.

Data & sources

Assessment data
2024–25 school year
NCES CCD vintage
2024
Census ACS 5-year vintage
2020-2024
Last updated
September 4, 2026
Methodology version
0.14.0

Cross-state metro note: This metro spans state lines. Both states use Smarter Balanced assessments with a common scale for grades 3–8 ELA/math. Context-adjusted ranks are computed within each state's testing context, then aggregated across the metro.

Source files (3)

SchoolDecoder publishes context-adjusted residuals, not causal estimates. Decoded Rank is one signal — not a verdict on teaching quality. Read about limitations →