Eastin Arcola: 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	41,322	2382.3	− 2436	−53.7	× 21 / 123	−9.2
4	41,323	2481.6	− 2485	−3.4	× 24 / 123	−0.7
5	41,326	2405.6	− 2528	−122.4	× 21 / 123	−20.9
6	41,327	2497.4	− 2552	−54.6	× 21 / 123	−9.3
7	41,330	2478.7	− 2567	−88.3	× 22 / 123	−15.8
8	41,331	2486.2	− 2586	−99.8	× 14 / 123	−11.4
Sum, rounded to a whole point						−67

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	38,226	2429.4	− 2436	−6.6	× 23 / 120	−1.3
4	38,229	2466.2	− 2485	−18.8	× 21 / 120	−3.3
5	38,231	2446.9	− 2528	−81.1	× 19 / 120	−12.8
6	38,233	2494.7	− 2552	−57.3	× 23 / 120	−11
7	38,235	2537.4	− 2567	−29.6	× 18 / 120	−4.4
8	38,236	2540.9	− 2586	−45.1	× 16 / 120	−6
Sum, rounded to a whole point						−39

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	39,132	2405.8	− 2436	−30.2	× 24 / 137	−5.3
4	39,135	2434.9	− 2485	−50.1	× 22 / 137	−8
5	39,137	2436.9	− 2528	−91.1	× 27 / 137	−18
6	39,138	2552.2	− 2552	0.2	× 15 / 137	0
7	39,140	2509.8	− 2567	−57.2	× 27 / 137	−11.3
8	39,143	2522.7	− 2586	−63.3	× 22 / 137	−10.2
Sum, rounded to a whole point						−53

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	39,154	2370.9	− 2436	−65.1	× 23 / 134	−11.2
4	39,155	2471.7	− 2485	−13.3	× 23 / 134	−2.3
5	39,158	2490.5	− 2528	−37.5	× 24 / 134	−6.7
6	39,159	2483.6	− 2552	−68.4	× 25 / 134	−12.8
7	39,162	2566.5	− 2567	−0.5	× 16 / 134	−0.1
8	39,163	2540.7	− 2586	−45.3	× 23 / 134	−7.8
Sum, rounded to a whole point						−41

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	39,300	2380.8	− 2436	−55.2	× 22 / 136	−8.9
4	39,301	2430.2	− 2485	−54.8	× 21 / 136	−8.5
5	39,302	2471.5	− 2528	−56.5	× 25 / 136	−10.4
6	39,303	2538.9	− 2552	−13.1	× 22 / 136	−2.1
7	39,304	2510.4	− 2567	−56.6	× 26 / 136	−10.8
8	39,305	2588.3	− 2586	2.3	× 20 / 136	0.3
Sum, rounded to a whole point						−40

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	39,063	2386.3	− 2436	−49.7	× 17 / 127	−6.7
4	39,064	2411.7	− 2485	−73.3	× 23 / 127	−13.3
5	39,065	2412.4	− 2528	−115.6	× 23 / 127	−20.9
6	39,066	2472.9	− 2552	−79.1	× 22 / 127	−13.7
7	39,067	2509.9	− 2567	−57.1	× 17 / 127	−7.6
8	39,068	2518.6	− 2586	−67.4	× 25 / 127	−13.3
Sum, rounded to a whole point						−75

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	39,116	2399.4	− 2436	−36.6	× 27 / 130	−7.6
4	39,117	2432.7	− 2485	−52.3	× 18 / 130	−7.2
5	39,118	2433.6	− 2528	−94.4	× 20 / 130	−14.5
6	39,119	2443.0	− 2552	−109	× 26 / 130	−21.8
7	39,120	2500.9	− 2567	−66.1	× 16 / 130	−8.1
8	39,121	2514.8	− 2586	−71.2	× 23 / 130	−12.6
Sum, rounded to a whole point						−72

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	38,944	2414.5	− 2436	−21.5	× 22 / 135	−3.5
4	38,945	2389.3	− 2485	−95.7	× 29 / 135	−20.6
5	38,946	2457.5	− 2528	−70.5	× 19 / 135	−9.9
6	38,947	2431.1	− 2552	−120.9	× 21 / 135	−18.8
7	38,948	2432.2	− 2567	−134.8	× 28 / 135	−28
8	38,949	2537.0	− 2586	−49	× 16 / 135	−5.8
Sum, rounded to a whole point						−87

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	38,715	2408.8	− 2436	−27.2	× 19 / 138	−3.7
4	38,716	2409.2	− 2485	−75.8	× 24 / 138	−13.2
5	38,717	2394.5	− 2528	−133.5	× 30 / 138	−29
6	38,718	2434.1	− 2552	−117.9	× 18 / 138	−15.4
7	38,719	2462.6	− 2567	−104.4	× 22 / 138	−16.6
8	38,720	2451.0	− 2586	−135	× 25 / 138	−24.5
Sum, rounded to a whole point						−102

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −67, −39, −53, −41, −40, −75, −72, −87, −102 → −64
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 28 · 2016→2017: 14 · 2017→2018: 12 · 2018→2019: 1 · 2019→2022: 35 · 2022→2023: 3 · 2023→2024: 15 · 2024→2025: 15 → average 15.4
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 15.4 × 2.66 = 41. Upper limit −23, lower limit −105.

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.