Albert F. Biella Elementary: 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	95,231	2416.0	− 2436	−20	× 63 / 239	−5.3
4	95,232	2414.9	− 2485	−70.1	× 50 / 239	−14.7
5	95,235	2454.3	− 2528	−73.7	× 73 / 239	−22.5
6	95,236	2449.5	− 2552	−102.5	× 53 / 239	−22.7
Sum, rounded to a whole point						−65

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	88,455	2405.6	− 2436	−30.4	× 46 / 214	−6.5
4	88,458	2437.7	− 2485	−47.3	× 54 / 214	−11.9
5	88,459	2446.2	− 2528	−81.8	× 48 / 214	−18.3
6	88,462	2464.9	− 2552	−87.1	× 66 / 214	−26.9
Sum, rounded to a whole point						−64

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	91,014	2404.7	− 2436	−31.3	× 51 / 191	−8.4
4	91,017	2425.2	− 2485	−59.8	× 43 / 191	−13.5
5	91,018	2473.6	− 2528	−54.4	× 54 / 191	−15.4
6	91,021	2475.8	− 2552	−76.2	× 43 / 191	−17.2
Sum, rounded to a whole point						−54

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	91,870	2413.2	− 2436	−22.8	× 54 / 195	−6.3
4	91,871	2449.4	− 2485	−35.6	× 55 / 195	−10
5	91,872	2471.2	− 2528	−56.8	× 46 / 195	−13.4
6	91,873	2471.0	− 2552	−81	× 40 / 195	−16.6
Sum, rounded to a whole point						−46

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	92,116	2397.6	− 2436	−38.4	× 29 / 152	−7.3
4	92,117	2401.9	− 2485	−83.1	× 40 / 152	−21.9
5	92,118	2440.0	− 2528	−88	× 39 / 152	−22.6
6	92,119	2438.1	− 2552	−113.9	× 44 / 152	−33
Sum, rounded to a whole point						−85

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	92,028	2387.5	− 2436	−48.5	× 43 / 146	−14.3
4	92,029	2428.0	− 2485	−57	× 31 / 146	−12.1
5	92,030	2451.9	− 2528	−76.1	× 33 / 146	−17.2
6	92,031	2458.2	− 2552	−93.8	× 39 / 146	−25.1
Sum, rounded to a whole point						−69

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	91,957	2384.8	− 2436	−51.2	× 28 / 129	−11.1
4	91,958	2414.4	− 2485	−70.6	× 37 / 129	−20.2
5	91,959	2449.0	− 2528	−79	× 30 / 129	−18.4
6	91,960	2470.0	− 2552	−82	× 34 / 129	−21.6
Sum, rounded to a whole point						−71

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	91,667	2377.7	− 2436	−58.3	× 29 / 122	−13.9
4	91,668	2412.0	− 2485	−73	× 32 / 122	−19.1
5	91,669	2470.9	− 2528	−57.1	× 33 / 122	−15.4
6	91,670	2482.6	− 2552	−69.4	× 28 / 122	−15.9
Sum, rounded to a whole point						−64

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −65, −64, −54, −46, −85, −69, −71, −64 → −64.8
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 1 · 2016→2017: 10 · 2017→2019: 8 · 2019→2022: 39 · 2022→2023: 16 · 2023→2024: 2 · 2024→2025: 7 → 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 −33.1, lower limit −96.5.

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.