Museum: 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	75,169	2459.6	− 2436	23.6	× 25 / 153	3.9
4	75,170	2491.1	− 2485	6.1	× 24 / 153	1
5	75,173	2554.2	− 2528	26.2	× 26 / 153	4.5
6	75,174	2541.2	− 2552	−10.8	× 27 / 153	−1.9
7	75,177	2561.3	− 2567	−5.7	× 24 / 153	−0.9
8	75,178	2572.1	− 2586	−13.9	× 27 / 153	−2.5
Sum, rounded to a whole point						4

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	69,873	2453.8	− 2436	17.8	× 26 / 148	3.1
4	69,874	2497.7	− 2485	12.7	× 26 / 148	2.2
5	69,877	2497.8	− 2528	−30.2	× 24 / 148	−4.9
6	69,879	2530.0	− 2552	−22	× 26 / 148	−3.9
7	69,881	2559.2	− 2567	−7.8	× 25 / 148	−1.3
8	69,883	2541.5	− 2586	−44.5	× 21 / 148	−6.3
Sum, rounded to a whole point						−11

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	71,707	2459.7	− 2436	23.7	× 23 / 147	3.7
4	71,709	2489.0	− 2485	4	× 26 / 147	0.7
5	71,711	2543.8	− 2528	15.8	× 27 / 147	2.9
6	71,713	2541.3	− 2552	−10.7	× 24 / 147	−1.7
7	71,715	2545.3	− 2567	−21.7	× 23 / 147	−3.4
8	71,718	2573.2	− 2586	−12.8	× 24 / 147	−2.1
Sum, rounded to a whole point						0

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	71,852	2473.3	− 2436	37.3	× 24 / 148	6
4	71,854	2487.8	− 2485	2.8	× 27 / 148	0.5
5	71,856	2495.8	− 2528	−32.2	× 24 / 148	−5.2
6	71,858	2545.8	− 2552	−6.2	× 26 / 148	−1.1
7	71,860	2551.2	− 2567	−15.8	× 26 / 148	−2.8
8	71,862	2561.4	− 2586	−24.6	× 21 / 148	−3.5
Sum, rounded to a whole point						−6

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	72,341	2425.7	− 2436	−10.3	× 23 / 155	−1.5
4	72,342	2542.6	− 2485	57.6	× 28 / 155	10.4
5	72,343	2537.9	− 2528	9.9	× 25 / 155	1.6
6	72,344	2528.4	− 2552	−23.6	× 28 / 155	−4.3
7	72,345	2590.4	− 2567	23.4	× 27 / 155	4.1
8	72,346	2571.8	− 2586	−14.2	× 24 / 155	−2.2
Sum, rounded to a whole point						8

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	70,826	2454.1	− 2436	18.1	× 20 / 136	2.7
4	70,827	2542.3	− 2485	57.3	× 23 / 136	9.7
5	70,828	2468.3	− 2528	−59.7	× 22 / 136	−9.7
6	70,829	2541.4	− 2552	−10.6	× 23 / 136	−1.8
7	70,830	2524.4	− 2567	−42.6	× 26 / 136	−8.1
8	70,831	2546.9	− 2586	−39.1	× 22 / 136	−6.3
Sum, rounded to a whole point						−14

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	72,431	2464.2	− 2436	28.2	× 20 / 116	4.9
4	72,432	2536.5	− 2485	51.5	× 24 / 116	10.7
5	72,433	2580.6	− 2528	52.6	× 23 / 116	10.4
6	72,434	2510.2	− 2552	−41.8	× 14 / 116	−5
7	72,435	2626.1	− 2567	59.1	× 20 / 116	10.2
8	72,436	2537.0	− 2586	−49	× 15 / 116	−6.3
Sum, rounded to a whole point						25

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	72,425	2472.0	− 2436	36	× 27 / 148	6.6
4	72,426	2500.9	− 2485	15.9	× 28 / 148	3
5	72,427	2543.7	− 2528	15.7	× 24 / 148	2.5
6	72,428	2528.0	− 2552	−24	× 25 / 148	−4.1
7	72,429	2555.0	− 2567	−12	× 23 / 148	−1.9
8	72,430	2576.2	− 2586	−9.8	× 21 / 148	−1.4
Sum, rounded to a whole point						5

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	72,407	2437.4	− 2436	1.4	× 26 / 134	0.3
4	72,408	2496.6	− 2485	11.6	× 23 / 134	2
5	72,409	2499.9	− 2528	−28.1	× 25 / 134	−5.2
6	72,410	2518.7	− 2552	−33.3	× 26 / 134	−6.5
7	72,411	2576.2	− 2567	9.2	× 19 / 134	1.3
8	72,412	2576.3	− 2586	−9.7	× 15 / 134	−1.1
Sum, rounded to a whole point						−9

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	72,123	2442.3	− 2436	6.3	× 19 / 144	0.8
4	72,124	2468.1	− 2485	−16.9	× 29 / 144	−3.4
5	72,125	2487.7	− 2528	−40.3	× 27 / 144	−7.6
6	72,126	2537.9	− 2552	−14.1	× 24 / 144	−2.4
7	72,127	2520.9	− 2567	−46.1	× 25 / 144	−8
8	72,128	2550.6	− 2586	−35.4	× 20 / 144	−4.9
Sum, rounded to a whole point						−25

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. 4, −11, 0, −6, 8, −14, 25, 5, −9, −25 → −2.3
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 15 · 2016→2017: 11 · 2017→2018: 6 · 2018→2019: 14 · 2019→2021: 22 · 2021→2022: 39 · 2022→2023: 20 · 2023→2024: 14 · 2024→2025: 16 → average 17.4
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 17.4 × 2.66 = 46.3. Upper limit 44, lower limit −48.6.

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.