Tamarisk: math · Schoolio

The shaded band is this school's normal range. If nothing about how it works changes, nearly every future year should land inside it. Zero means the typical student just meets the state standard. The small numbers under the years are how many students were tested.

Step 1 · Each year's result

For each grade tested, take the average (mean) scale score from the California Department of Education's results file, and subtract the lowest score that counts as "Standard Met" for that grade. That is the grade's distance from standard. Weight each grade by its share of the students tested, then add the grades up. Grades where the state hides the average because ten or fewer students tested are left out entirely.

2015 from sb_ca2015_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	35,573	2343.1	− 2436	−92.9	× 107 / 377	−26.4
4	35,575	2379.5	− 2485	−105.5	× 110 / 377	−30.8
5	35,577	2413.4	− 2528	−114.6	× 83 / 377	−25.2
6	35,579	2417.7	− 2552	−134.3	× 77 / 377	−27.4
Sum, rounded to a whole point						−110

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,215	2341.3	− 2436	−94.7	× 126 / 436	−27.4
4	33,217	2387.1	− 2485	−97.9	× 109 / 436	−24.5
5	33,219	2436.4	− 2528	−91.6	× 113 / 436	−23.7
6	33,220	2407.8	− 2552	−144.2	× 88 / 436	−29.1
Sum, rounded to a whole point						−105

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,795	2323.1	− 2436	−112.9	× 101 / 432	−26.4
4	33,797	2372.9	− 2485	−112.1	× 130 / 432	−33.7
5	33,799	2415.5	− 2528	−112.5	× 117 / 432	−30.5
6	33,801	2453.5	− 2552	−98.5	× 84 / 432	−19.2
Sum, rounded to a whole point						−110

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,826	2364.6	− 2436	−71.4	× 127 / 361	−25.1
4	33,827	2381.0	− 2485	−104	× 108 / 361	−31.1
5	33,830	2430.5	− 2528	−97.5	× 126 / 361	−34
Sum, rounded to a whole point						−90

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	34,003	2315.2	− 2436	−120.8	× 110 / 349	−38.1
4	34,004	2375.8	− 2485	−109.2	× 132 / 349	−41.3
5	34,005	2400.8	− 2528	−127.2	× 107 / 349	−39
Sum, rounded to a whole point						−118

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,922	2344.7	− 2436	−91.3	× 116 / 354	−29.9
4	33,923	2376.5	− 2485	−108.5	× 115 / 354	−35.2
5	33,924	2413.2	− 2528	−114.8	× 123 / 354	−39.9
Sum, rounded to a whole point						−105

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,971	2354.3	− 2436	−81.7	× 127 / 357	−29.1
4	33,972	2387.6	− 2485	−97.4	× 109 / 357	−29.7
5	33,973	2406.0	− 2528	−122	× 121 / 357	−41.4
Sum, rounded to a whole point						−100

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,829	2332.3	− 2436	−103.7	× 110 / 341	−33.5
4	33,830	2394.9	− 2485	−90.1	× 123 / 341	−32.5
5	33,831	2417.0	− 2528	−111	× 108 / 341	−35.2
Sum, rounded to a whole point						−101

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,690	2331.7	− 2436	−104.3	× 123 / 346	−37.1
4	33,691	2363.4	− 2485	−121.6	× 104 / 346	−36.6
5	33,692	2397.0	− 2528	−131	× 119 / 346	−45.1
Sum, rounded to a whole point						−119

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −110, −105, −110, −90, −118, −105, −100, −101, −119 → −106.4
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 5 · 2016→2017: 5 · 2017→2018: 20 · 2018→2019: 28 · 2019→2022: 13 · 2022→2023: 5 · 2023→2024: 1 · 2024→2025: 18 → average 11.9
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 11.9 × 2.66 = 31.7. Upper limit −74.7, lower limit −138.1.

Why 2.66? It is the standard factor from quality control, the work of Walter Shewhart and W. Edwards Deming. It turns "how much the result typically changes in a year" into "how far it can wander by chance alone".

Years with no result (no state tests were given in spring 2020) are skipped: the year-to-year change runs from the last year with a result to the next one.

Step 3 · Free or reduced-price meals

The share of enrolled students eligible for free or reduced-price meals. From 2014–15, 2015–16, 2016–17, 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.