Chinook Middle School

Bellevue, WA · Grades 6–8

Seattle-Tacoma-Bellevue, WA

Neighborhood

Decoded Rank

All factors combined

Middle 40% decoded

#391 of 680

Seattle-Tacoma-Bellevue, WA schools

Performing as Expected

#822 in WA

Achievement Rank

Raw test performance

Middle 40% achievement

#234 of 680

Seattle-Tacoma-Bellevue, WA schools

#312 in WA

places from achievement to Decoded Rank

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

Data confidence:High1500 students tested 8 years98% 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: #391 of 680

in Seattle-Tacoma-Bellevue, WA schools

Raw test scores rank this school #234, 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 #391.

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

  • About averagePerforms 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?

  • About averageEquity within the schoolCounts for 15% of the rank

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

  • LowDirection 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.

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 35%46-1.4
Students gain ground year over year 30%61+3.2
Equity within the school 15%48-0.4
Direction over recent years 10%0-5.0
Most students were tested 10%98+4.8

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 →

All Rankings

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

ScopeAchievementDecodedShift
Seattle-Tacoma-Bellevue, WA (680 schools)#234#391
WA (1506 schools)#312#822
Among similar schools (6 peers)#2#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
752
Free/reduced-price lunch
24.1%
Student-teacher ratio
18.8:1
Locale
Suburb, large
School type
Regular public school
Enrollment model
Neighborhood attendance area
Neighborhood median income
$250,001ACS tract proxy
Neighborhood poverty
0.0%ACS tract proxy
SES index
93.3
Assessment data year
2025
CCD year
2024
ACS vintage
2020-2024

Within Bellevue School District: #11 of 21.Middle quintile in district. 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 standard16%
  • Level 2 — Approaching standard20%
  • Level 3 — Meets standard (proficient)31%
  • Level 4 — Exceeds standard31%

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.

SchoolAchievementDecodedShiftStoryConfidence
Clyde Hill Elementary#163#590High
Medina Elementary School#2#4High
Bellevue High School Rankings coming soon.
Bellevue Digital Discovery Rankings coming soon.
Cherry Crest Elementary School#14#141High

Similar Schools

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

SchoolAchievementDecodedShiftStoryConfidence
Anacortes High School Rankings coming soon.
Northshore Middle School#236#324High
Kenmore Middle School#287#491High
Liberty Middle School#165#314High
Three Rivers Home Link Rankings coming soon.

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#391
2024#217#190
2023#196#160

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

Trajectory

2023: percentile 752024: percentile 702025: percentile 46

Trending down

Based on 3 years (2023–2025).

Slope: -14.4 pct/yr (95% CI -86.4 to 57.7)

Low confidence

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 6th grade here in 2015 lost 9 proficiency points by 8th grade.

Based on 16 cohorts across math + ELA.

Learning rate: +1.8 proficiency points/yr (95% CI -3.2 to 6.7)

Cohort 20152016201720182019202320242025 Slope
ELA · started 8th in 2015
G8
309
ELA · started 7th in 2015
G7
310
G8
317
+7.9
ELA · started 6th in 2015
G6
308
G7
312
G8
298
-4.6
ELA · started 6th in 2016
G6
304
G7
307
G8
300
-2.2
ELA · started 6th in 2017
G6
286
G7
291
G8
303
+8.3
ELA · started 6th in 2018
G6
293
G7
319
+25.9
ELA · started 6th in 2019
G6
298
ELA · started 8th in 2023
G8
296
ELA · started 7th in 2023
G7
297
G8
281
-16.5
ELA · started 6th in 2023
G6
278
G7
287
G8
280
+1.0
ELA · started 6th in 2024
G6
270
G7
286
+16.4
ELA · started 6th in 2025
G6
271
Math · started 8th in 2015
G8
322
Math · started 7th in 2015
G7
320
G8
326
+6.4
Math · started 6th in 2015
G6
306
G7
315
G8
312
+2.9
Math · started 6th in 2016
G6
310
G7
311
G8
300
-5.0
Math · started 6th in 2017
G6
296
G7
294
G8
298
+1.2
Math · started 6th in 2018
G6
296
G7
297
+0.6
Math · started 6th in 2019
G6
302
Math · started 8th in 2023
G8
268
Math · started 7th in 2023
G7
285
G8
274
-11.6
Math · started 6th in 2023
G6
268
G7
279
G8
265
-1.3
Math · started 6th in 2024
G6
276
G7
280
+4.4
Math · started 6th in 2025
G6
273

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)
-0.05 (95% CI: -0.06 to -0.04)

SES index components

SES method
Blended SES index (ACS + FRL)
SES index value
93.3
FRL %
24.1%
ELL %
SPED %
Tract median income (ACS 5-year)
$250,001
Tract poverty rate
0.0%
Tract % bachelor's+
80.8%

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.

Data & sources

Assessment data
2024–25 school year
NCES CCD vintage
2024
Census ACS 5-year vintage
2020-2024
Last updated
May 29, 2026
Methodology version
0.2.0

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