Ann B. Leavenworth: 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
3	11,191	2399.5	− 2436	−36.5	× 135 / 443	−11.1
4	11,192	2452.5	− 2485	−32.5	× 117 / 443	−8.6
5	11,195	2441.6	− 2528	−86.4	× 98 / 443	−19.1
6	11,196	2486.4	− 2552	−65.6	× 93 / 443	−13.8
Sum, rounded to a whole point						−53

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,209	2415.4	− 2436	−20.6	× 120 / 451	−5.5
4	10,211	2456.0	− 2485	−29	× 126 / 451	−8.1
5	10,212	2500.8	− 2528	−27.2	× 112 / 451	−6.8
6	10,215	2499.1	− 2552	−52.9	× 93 / 451	−10.9
Sum, rounded to a whole point						−31

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,537	2448.9	− 2436	12.9	× 121 / 457	3.4
4	10,538	2453.9	− 2485	−31.1	× 110 / 457	−7.5
5	10,541	2476.6	− 2528	−51.4	× 123 / 457	−13.8
6	10,543	2537.9	− 2552	−14.1	× 103 / 457	−3.2
Sum, rounded to a whole point						−21

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,548	2441.5	− 2436	5.5	× 116 / 461	1.4
4	10,550	2465.8	− 2485	−19.2	× 124 / 461	−5.2
5	10,553	2491.5	− 2528	−36.5	× 100 / 461	−7.9
6	10,554	2518.8	− 2552	−33.2	× 121 / 461	−8.7
Sum, rounded to a whole point						−20

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,629	2454.8	− 2436	18.8	× 116 / 442	4.9
4	10,630	2479.6	− 2485	−5.4	× 113 / 442	−1.4
5	10,631	2497.3	− 2528	−30.7	× 121 / 442	−8.4
6	10,632	2520.8	− 2552	−31.2	× 92 / 442	−6.5
Sum, rounded to a whole point						−11

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,622	2415.1	− 2436	−20.9	× 118 / 464	−5.3
4	10,623	2422.1	− 2485	−62.9	× 118 / 464	−16
5	10,624	2429.5	− 2528	−98.5	× 113 / 464	−24
6	10,625	2516.9	− 2552	−35.1	× 115 / 464	−8.7
Sum, rounded to a whole point						−54

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,610	2403.3	− 2436	−32.7	× 116 / 465	−8.2
4	10,611	2454.8	− 2485	−30.2	× 119 / 465	−7.7
5	10,612	2465.9	− 2528	−62.1	× 113 / 465	−15.1
6	10,613	2474.8	− 2552	−77.2	× 117 / 465	−19.4
Sum, rounded to a whole point						−50

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,576	2409.0	− 2436	−27	× 108 / 445	−6.6
4	10,577	2439.7	− 2485	−45.3	× 111 / 445	−11.3
5	10,578	2469.7	− 2528	−58.3	× 117 / 445	−15.3
6	10,579	2508.7	− 2552	−43.3	× 109 / 445	−10.6
Sum, rounded to a whole point						−44

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,553	2404.2	− 2436	−31.8	× 106 / 429	−7.9
4	10,554	2454.2	− 2485	−30.8	× 105 / 429	−7.5
5	10,555	2475.4	− 2528	−52.6	× 108 / 429	−13.2
6	10,556	2512.5	− 2552	−39.5	× 110 / 429	−10.1
Sum, rounded to a whole point						−39

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −53, −31, −21, −20, −11, −54, −50, −44, −39 → −35.9
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 22 · 2016→2017: 10 · 2017→2018: 1 · 2018→2019: 9 · 2019→2022: 43 · 2022→2023: 4 · 2023→2024: 6 · 2024→2025: 5 → average 12.5
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 12.5 × 2.66 = 33.3. Upper limit −2.6, lower limit −69.2.

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.