Oak Tree Community Day: math

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
6	35,547	2357.9	− 2552	−194.1	× 10 / 26	−74.7
8	35,551	2379.8	− 2586	−206.2	× 16 / 26	−126.9
Sum, rounded to a whole point						−202

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	33,187	2359.6	− 2552	−192.4	× 14 / 58	−46.4
7	33,189	2332.9	− 2567	−234.1	× 15 / 58	−60.5
8	33,191	2429.6	− 2586	−156.4	× 29 / 58	−78.2
Sum, rounded to a whole point						−185

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
5	33,762	2332.2	− 2528	−195.8	× 12 / 69	−34.1
6	33,763	2371.9	− 2552	−180.1	× 18 / 69	−47
7	33,765	2397.7	− 2567	−169.3	× 19 / 69	−46.6
8	33,767	2368.2	− 2586	−217.8	× 20 / 69	−63.1
Sum, rounded to a whole point						−191

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
4	33,786	2331.6	− 2485	−153.4	× 11 / 62	−27.2
5	33,788	2327.9	− 2528	−200.1	× 12 / 62	−38.7
6	33,790	2315.8	− 2552	−236.2	× 18 / 62	−68.6
7	33,792	2361.4	− 2567	−205.6	× 21 / 62	−69.6
Sum, rounded to a whole point						−204

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	33,965	2381.3	− 2552	−170.7	× 11 / 54	−34.8
7	33,966	2383.5	− 2567	−183.5	× 24 / 54	−81.6
8	33,967	2371.9	− 2586	−214.1	× 19 / 54	−75.3
Sum, rounded to a whole point						−192

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
8	33,878	2394.2	− 2586	−191.8	× 15 / 15	−191.8
Sum, rounded to a whole point						−192

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	33,925	2364.4	− 2552	−187.6	× 12 / 44	−51.2
7	33,926	2364.4	− 2567	−202.6	× 15 / 44	−69.1
8	33,927	2351.9	− 2586	−234.1	× 17 / 44	−90.4
Sum, rounded to a whole point						−211

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	33,784	2350.8	− 2567	−216.2	× 16 / 36	−96.1
8	33,785	2353.3	− 2586	−232.7	× 20 / 36	−129.3
Sum, rounded to a whole point						−225

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	33,644	2308.0	− 2552	−244	× 11 / 44	−61
7	33,645	2346.7	− 2567	−220.3	× 18 / 44	−90.1
8	33,646	2363.0	− 2586	−223	× 15 / 44	−76
Sum, rounded to a whole point						−227

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −202, −185, −191, −204, −192, −192, −211, −225, −227 → −203.2
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 17 · 2016→2017: 6 · 2017→2018: 13 · 2018→2019: 12 · 2019→2022: 0 · 2022→2023: 19 · 2023→2024: 14 · 2024→2025: 2 → average 10.4
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 10.4 × 2.66 = 27.7. Upper limit −175.5, lower limit −230.9.

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.