Sauvie Island School
Portland, OR · Grades K–8 · Charter
Portland-Vancouver-Hillsboro, OR-WA
CharterDecoded Rank
All factors combined
Top 30% decoded
#70 of 430
plausibly #32–145
Portland-Vancouver-Hillsboro, OR-WA schools
★ Above Expected
#113 in OR
Achievement Rank
Raw test performance
Top 30% achievement
#74 of 430
Portland-Vancouver-Hillsboro, OR-WA schools
#81 in OR
★Strong by Both Measures
Students score highly, and the school still stands out after accounting for context — students also tend to gain ground while enrolled.
Data confidence:High283 students tested 7 years99% 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: #70 of 430
in Portland-Vancouver-Hillsboro, OR-WA schools
Each component below is scored on a 0–100 within-metro scale. A qualitative band summarizes where the school lands.
- StrongPerforms above what its context predictsCounts for 35% of the rank
After accounting for income and demographics, does this school beat what the data would predict?
- Above averageStudents gain ground year over yearCounts for 30% of the rank
Are kids at this school learning faster than typical for the metro?
- Below averageEquity within the schoolCounts for 15% of the rank
Are students clustered at similar levels, or split between top and bottom?
- Thin dataDirection over recent yearsCounts for 10% of the rank
Is this school's Decoded Rank trending up or down across the years we have data for?
- StrongMost students were testedCounts for 10% 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.
| Component | Weight | Percentile | Contribution |
|---|---|---|---|
| Performs above what its context predicts | 35% | 86 | +12.7 |
| Students gain ground year over year | 30% | 72 | +6.7 |
| Equity within the school | 15% | 37 | -1.9 |
| Direction over recent years · thin data | 10% | 50 | +0.0 |
| Most students were tested | 10% | 99 | +4.9 |
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 →
All Rankings
How this school ranks across the metro, state, and among demographic peers.
| Scope | Achievement | Decoded | Shift |
|---|---|---|---|
| Portland-Vancouver-Hillsboro, OR-WA (430 schools) | #74 | #70 | |
| OR (667 schools) | #81 | #113 | |
| Among similar schools (6 peers) | #4 | #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
- 214
- Free/reduced-price lunch
- 31.8%
- Student-teacher ratio
- 15.3:1
- Locale
- Rural, fringe
- School type
- Charter school
- Enrollment model
- Charter enrollment
- Neighborhood median income
- $109,607ACS tract proxy
- Neighborhood poverty
- 0.0%ACS tract proxy
- SES index
- 85.9
- Assessment data year
- 2024
- CCD year
- 2023
- ACS vintage
- 2020-2024
Within Scappoose SD 1J: #1 of 4. 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.
Two distinct groups are visible: a strong cluster at the top and a struggling cluster at the bottom.
- Level 1 — Below standard17%
- Level 2 — Approaching standard22%
- Level 3 — Meets standard (proficient)28%
- Level 4 — Exceeds standard32%
Why this matters. A bimodal distribution often reflects two student populations served side-by-side (for example a gifted or honors track alongside a general-population cohort). Aggregate scores can hide this. Look at the school's program mix when comparing.
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.
- Skyline Elementary School3.6 mi
- Sitton Elementary School5.0 mi
- Sato Elementary School5.6 mi
- James John Elementary School5.7 mi
- George Middle School5.9 mi
| School | Achievement | Decoded | Shift | Story | Confidence |
|---|---|---|---|---|---|
| Skyline Elementary School | Rankings coming soon. | ||||
| Sitton Elementary School | #205 | #222 | Typical Profile | High | |
| Sato Elementary School | #19 | #13 | ★Strong by Both Measures | High | |
| James John Elementary School | #329 | #427 | Lower by Both Measures | Medium | |
| George Middle School | #400 | #118 | Typical Profile | Medium | |
Similar Schools
Schools with comparable demographics, income, and size. Both rank columns shown for direct comparison.
| School | Achievement | Decoded | Shift | Story | Confidence |
|---|---|---|---|---|---|
| Irvington Elementary School | #86 | #379 | High Scores, Context Matters | High | |
| Ewing Young Elementary School | #43 | #145 | High Scores, Context Matters | Medium | |
| Bend International School | #10 | #30 | Typical Profile | Medium | |
| Banks Middle School | #305 | Est. #381 | Typical Profile | Low | |
| Bolton Primary School | #18 | #65 | ★Strong by Both Measures | High |
Historical Ranks
Year-by-year decoded and achievement ranks. Pandemic-affected years are excluded — we don't interpolate scores across the gap.
| Year | Achievement | Decoded | Shift |
|---|---|---|---|
| 2024 | #74 | #70 |
Note: assessment transitions (where a state changes its test) are footnoted on the methodology page; trends are not computed across breakpoints.
Trajectory
Not enough years yet
Trajectory will appear with 2025-26 data 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 5th grade here in 2023 lost 25 proficiency points by 6th grade — declining about 2× faster than the metro median.
Based on 26 cohorts across math + ELA.
Learning rate: -1.7 proficiency points/yr (95% CI -7.1 to 3.8)
Medium confidence
| Cohort | 2015 | 2016 | 2017 | 2018 | 2019 | 2023 | 2024 | Slope |
|---|---|---|---|---|---|---|---|---|
| ELA · started 8th in 2015 | G8 242 | — | ||||||
| ELA · started 7th in 2015 | G7 242 | G8 257 | +14.8 | |||||
| ELA · started 6th in 2015 | G6 242 | G7 259 | G8 275 | +16.7 | ||||
| ELA · started 5th in 2015 | G5 325 | G6 287 | G7 271 | G8 261 | -20.8 | |||
| ELA · started 4th in 2015 | G4 316 | G5 291 | G6 283 | G7 296 | G8 300 | -2.7 | ||
| ELA · started 3rd in 2015 | G3 271 | G4 267 | G5 248 | G6 295 | G7 295 | +7.7 | ||
| ELA · started 3rd in 2016 | G3 252 | G4 287 | G5 317 | G6 296 | +16.1 | |||
| ELA · started 3rd in 2017 | G3 321 | G4 317 | G5 329 | +4.2 | ||||
| ELA · started 3rd in 2018 | G3 304 | G4 312 | G8 282 | -5.4 | ||||
| ELA · started 3rd in 2019 | G3 304 | G7 283 | G8 265 | -7.1 | ||||
| ELA · started 6th in 2023 | G6 296 | G7 283 | -12.6 | |||||
| ELA · started 5th in 2023 | G5 275 | G6 250 | -24.7 | |||||
| ELA · started 4th in 2023 | G4 288 | G5 296 | +8.1 | |||||
| ELA · started 3rd in 2023 | G3 283 | G4 300 | +17.4 | |||||
| ELA · started 3rd in 2024 | G3 296 | — | ||||||
| Math · started 8th in 2015 | G8 232 | — | ||||||
| Math · started 7th in 2015 | G7 200 | G8 204 | +4.2 | |||||
| Math · started 6th in 2015 | G6 225 | G7 241 | G8 204 | -10.5 | ||||
| Math · started 5th in 2015 | G5 317 | G6 254 | G7 275 | G8 250 | -17.9 | |||
| Math · started 4th in 2015 | G4 271 | G5 261 | G6 248 | G7 248 | G8 286 | +1.8 | ||
| Math · started 3rd in 2015 | G3 254 | G4 296 | G5 257 | G6 242 | G7 275 | -1.3 | ||
| Math · started 3rd in 2016 | G3 270 | G4 317 | G5 317 | G6 262 | -2.2 | |||
| Math · started 3rd in 2017 | G3 304 | G4 300 | G5 292 | -6.3 | ||||
| Math · started 3rd in 2018 | G3 283 | G4 304 | G8 223 | -14.5 | ||||
| Math · started 3rd in 2019 | G3 271 | G7 283 | G8 274 | +1.3 | ||||
| Math · started 6th in 2023 | G6 250 | G7 258 | +8.4 | |||||
| Math · started 5th in 2023 | G5 271 | G6 233 | -37.6 | |||||
| Math · started 4th in 2023 | G4 271 | G5 288 | +16.4 | |||||
| Math · started 3rd in 2023 | G3 287 | G4 295 | +8.6 | |||||
| Math · started 3rd in 2024 | G3 267 | — |
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.
- Shrunk Alpha (95% CI)
- +0.58 (95% CI: +0.54 to +0.63)
SES index components
- SES method
- Blended SES index (ACS + FRL)
- SES index value
- 85.9
- FRL %
- 31.8%
- ELL %
- 6.0% · OR ODE At-A-Glance (Ever English Learners)
- SPED %
- 18.0% · OR ODE At-A-Glance
- Tract median income (ACS 5-year)
- $109,607
- Tract poverty rate
- 0.0%
- Tract % bachelor's+
- 47.8%
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.