Bay Area Technology: 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	2,267	2431.0	− 2552	−121	× 45 / 164	−33.2
7	2,269	2452.1	− 2567	−114.9	× 43 / 164	−30.1
8	2,271	2475.0	− 2586	−111	× 51 / 164	−34.5
11	2,273	2525.7	− 2628	−102.3	× 25 / 164	−15.6
Sum, rounded to a whole point						−113

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	1,948	2435.7	− 2552	−116.3	× 47 / 156	−35
7	1,950	2448.8	− 2567	−118.2	× 45 / 156	−34.1
8	1,952	2454.1	− 2586	−131.9	× 44 / 156	−37.2
11	1,954	2492.5	− 2628	−135.5	× 20 / 156	−17.4
Sum, rounded to a whole point						−124

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,007	2569.3	− 2552	17.3	× 51 / 167	5.3
7	2,008	2499.6	− 2567	−67.4	× 45 / 167	−18.2
8	2,011	2523.4	− 2586	−62.6	× 38 / 167	−14.2
11	2,012	2555.7	− 2628	−72.3	× 33 / 167	−14.3
Sum, rounded to a whole point						−41

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,017	2455.9	− 2552	−96.1	× 47 / 173	−26.1
7	2,019	2455.5	− 2567	−111.5	× 46 / 173	−29.6
8	2,021	2457.4	− 2586	−128.6	× 41 / 173	−30.5
11	2,022	2493.7	− 2628	−134.3	× 39 / 173	−30.3
Sum, rounded to a whole point						−117

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,027	2446.1	− 2552	−105.9	× 46 / 167	−29.2
7	2,028	2450.5	− 2567	−116.5	× 48 / 167	−33.5
8	2,029	2483.9	− 2586	−102.1	× 47 / 167	−28.7
11	2,030	2463.5	− 2628	−164.5	× 26 / 167	−25.6
Sum, rounded to a whole point						−117

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,009	2401.7	− 2552	−150.3	× 54 / 175	−46.4
7	2,010	2446.8	− 2567	−120.2	× 50 / 175	−34.3
8	2,011	2471.3	− 2586	−114.7	× 48 / 175	−31.5
11	2,012	2467.6	− 2628	−160.4	× 23 / 175	−21.1
Sum, rounded to a whole point						−133

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	1,969	2427.9	− 2552	−124.1	× 46 / 200	−28.5
7	1,970	2467.1	− 2567	−99.9	× 53 / 200	−26.5
8	1,971	2481.9	− 2586	−104.1	× 49 / 200	−25.5
11	1,972	2482.1	− 2628	−145.9	× 52 / 200	−37.9
Sum, rounded to a whole point						−118

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	1,937	2423.1	− 2552	−128.9	× 27 / 175	−19.9
7	1,938	2469.0	− 2567	−98	× 42 / 175	−23.5
8	1,939	2487.3	− 2586	−98.7	× 51 / 175	−28.8
11	1,940	2488.6	− 2628	−139.4	× 55 / 175	−43.8
Sum, rounded to a whole point						−116

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	1,911	2431.0	− 2552	−121	× 17 / 119	−17.3
7	1,912	2475.1	− 2567	−91.9	× 26 / 119	−20.1
8	1,913	2487.3	− 2586	−98.7	× 43 / 119	−35.7
11	1,914	2495.1	− 2628	−132.9	× 33 / 119	−36.9
Sum, rounded to a whole point						−110

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −113, −124, −41, −117, −117, −133, −118, −116, −110 → −109.9
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 11 · 2016→2017: 83 · 2017→2018: 76 · 2018→2019: 0 · 2019→2022: 16 · 2022→2023: 15 · 2023→2024: 2 · 2024→2025: 6 → average 26.1
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 26.1 × 2.66 = 69.4. Upper limit −40.5, lower limit −179.3.

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.