Luther Burbank 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	44,418	2416.3	− 2436	−19.7	× 121 / 342	−7
4	44,419	2424.5	− 2485	−60.5	× 112 / 342	−19.8
5	44,422	2469.9	− 2528	−58.1	× 109 / 342	−18.5
Sum, rounded to a whole point						−45

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	41,143	2450.7	− 2436	14.7	× 87 / 337	3.8
4	41,146	2447.3	− 2485	−37.7	× 90 / 337	−10.1
5	41,147	2497.7	− 2528	−30.3	× 73 / 337	−6.6
6	41,150	2523.1	− 2552	−28.9	× 87 / 337	−7.5
Sum, rounded to a whole point						−20

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,167	2457.3	− 2436	21.3	× 98 / 348	6
4	42,169	2461.8	− 2485	−23.2	× 78 / 348	−5.2
5	42,171	2484.8	− 2528	−43.2	× 99 / 348	−12.3
6	42,172	2545.6	− 2552	−6.4	× 73 / 348	−1.3
Sum, rounded to a whole point						−13

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,179	2460.1	− 2436	24.1	× 93 / 362	6.2
4	42,182	2466.7	− 2485	−18.3	× 97 / 362	−4.9
5	42,183	2538.0	− 2528	10	× 77 / 362	2.1
6	42,186	2504.7	− 2552	−47.3	× 95 / 362	−12.4
Sum, rounded to a whole point						−9

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,322	2453.2	− 2436	17.2	× 84 / 353	4.1
4	42,323	2494.5	− 2485	9.5	× 91 / 353	2.4
5	42,324	2530.9	− 2528	2.9	× 93 / 353	0.8
6	42,325	2552.7	− 2552	0.7	× 85 / 353	0.2
Sum, rounded to a whole point						7

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,083	2429.6	− 2436	−6.4	× 96 / 379	−1.6
4	42,084	2460.9	− 2485	−24.1	× 87 / 379	−5.5
5	42,085	2492.4	− 2528	−35.6	× 101 / 379	−9.5
6	42,086	2479.2	− 2552	−72.8	× 95 / 379	−18.2
Sum, rounded to a whole point						−35

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,108	2431.4	− 2436	−4.6	× 94 / 377	−1.1
4	42,109	2451.4	− 2485	−33.6	× 105 / 377	−9.4
5	42,110	2477.7	− 2528	−50.3	× 85 / 377	−11.3
6	42,111	2491.0	− 2552	−61	× 93 / 377	−15
Sum, rounded to a whole point						−37

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	41,939	2409.9	− 2436	−26.1	× 97 / 410	−6.2
4	41,940	2452.0	− 2485	−33	× 112 / 410	−9
5	41,941	2476.5	− 2528	−51.5	× 105 / 410	−13.2
6	41,942	2474.5	− 2552	−77.5	× 96 / 410	−18.1
Sum, rounded to a whole point						−47

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	41,702	2420.2	− 2436	−15.8	× 99 / 408	−3.8
4	41,703	2431.0	− 2485	−54	× 95 / 408	−12.6
5	41,704	2478.4	− 2528	−49.6	× 114 / 408	−13.9
6	41,705	2488.8	− 2552	−63.2	× 100 / 408	−15.5
Sum, rounded to a whole point						−46

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −45, −20, −13, −9, 7, −35, −37, −47, −46 → −27.2
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 25 · 2016→2017: 7 · 2017→2018: 4 · 2018→2019: 16 · 2019→2022: 42 · 2022→2023: 2 · 2023→2024: 10 · 2024→2025: 1 → average 13.4
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 13.4 × 2.66 = 35.6. Upper limit 8.4, lower limit −62.8.

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.