Stratford 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	18,661	2368.8	− 2436	−67.2	× 43 / 178	−16.2
4	18,662	2420.2	− 2485	−64.8	× 23 / 178	−8.4
5	18,665	2445.8	− 2528	−82.2	× 23 / 178	−10.6
6	18,666	2454.5	− 2552	−97.5	× 31 / 178	−17
7	18,669	2439.7	− 2567	−127.3	× 29 / 178	−20.7
8	18,670	2499.9	− 2586	−86.1	× 29 / 178	−14
Sum, rounded to a whole point						−87

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	17,659	2412.5	− 2436	−23.5	× 25 / 172	−3.4
4	17,661	2432.0	− 2485	−53	× 37 / 172	−11.4
5	17,664	2462.7	− 2528	−65.3	× 28 / 172	−10.6
6	17,666	2476.7	− 2552	−75.3	× 22 / 172	−9.6
7	17,667	2483.7	− 2567	−83.3	× 30 / 172	−14.5
8	17,669	2498.6	− 2586	−87.4	× 30 / 172	−15.2
Sum, rounded to a whole point						−65

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,000	2412.3	− 2436	−23.7	× 24 / 179	−3.2
4	18,001	2452.1	− 2485	−32.9	× 31 / 179	−5.7
5	18,003	2433.6	− 2528	−94.4	× 39 / 179	−20.6
6	18,006	2492.7	− 2552	−59.3	× 30 / 179	−9.9
7	18,007	2474.1	− 2567	−92.9	× 23 / 179	−11.9
8	18,009	2429.0	− 2586	−157	× 32 / 179	−28.1
Sum, rounded to a whole point						−79

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,013	2424.1	− 2436	−11.9	× 38 / 180	−2.5
4	18,014	2462.1	− 2485	−22.9	× 24 / 180	−3.1
5	18,017	2470.7	− 2528	−57.3	× 29 / 180	−9.2
6	18,018	2464.0	− 2552	−88	× 33 / 180	−16.1
7	18,021	2497.1	− 2567	−69.9	× 31 / 180	−12
8	18,022	2535.1	− 2586	−50.9	× 25 / 180	−7.1
Sum, rounded to a whole point						−50

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,161	2404.8	− 2436	−31.2	× 31 / 187	−5.2
4	18,162	2498.6	− 2485	13.6	× 39 / 187	2.8
5	18,163	2473.0	− 2528	−55	× 24 / 187	−7.1
6	18,164	2514.0	− 2552	−38	× 30 / 187	−6.1
7	18,165	2515.0	− 2567	−52	× 30 / 187	−8.3
8	18,166	2541.5	− 2586	−44.5	× 33 / 187	−7.9
Sum, rounded to a whole point						−32

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,205	2402.3	− 2436	−33.7	× 32 / 192	−5.6
4	18,206	2407.2	− 2485	−77.8	× 33 / 192	−13.4
5	18,207	2421.9	− 2528	−106.1	× 41 / 192	−22.7
6	18,208	2413.7	− 2552	−138.3	× 30 / 192	−21.6
7	18,209	2480.7	− 2567	−86.3	× 32 / 192	−14.4
8	18,210	2458.3	− 2586	−127.7	× 24 / 192	−16
Sum, rounded to a whole point						−94

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,144	2439.1	− 2436	3.1	× 29 / 204	0.4
4	18,145	2430.3	− 2485	−54.7	× 32 / 204	−8.6
5	18,146	2463.0	− 2528	−65	× 33 / 204	−10.5
6	18,147	2443.0	− 2552	−109	× 44 / 204	−23.5
7	18,148	2451.5	− 2567	−115.5	× 32 / 204	−18.1
8	18,149	2508.8	− 2586	−77.2	× 34 / 204	−12.9
Sum, rounded to a whole point						−73

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,103	2409.3	− 2436	−26.7	× 30 / 211	−3.8
4	18,104	2458.4	− 2485	−26.6	× 29 / 211	−3.7
5	18,105	2442.1	− 2528	−85.9	× 37 / 211	−15.1
6	18,106	2443.3	− 2552	−108.7	× 38 / 211	−19.6
7	18,107	2478.9	− 2567	−88.1	× 44 / 211	−18.4
8	18,108	2517.8	− 2586	−68.2	× 33 / 211	−10.7
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	18,099	2415.0	− 2436	−21	× 24 / 189	−2.7
4	18,100	2418.6	− 2485	−66.4	× 28 / 189	−9.8
5	18,101	2502.7	− 2528	−25.3	× 28 / 189	−3.7
6	18,102	2454.8	− 2552	−97.2	× 35 / 189	−18
7	18,103	2488.5	− 2567	−78.5	× 33 / 189	−13.7
8	18,104	2471.3	− 2586	−114.7	× 41 / 189	−24.9
Sum, rounded to a whole point						−73

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −87, −65, −79, −50, −32, −94, −73, −71, −73 → −69.3
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: 14 · 2017→2018: 29 · 2018→2019: 18 · 2019→2022: 62 · 2022→2023: 21 · 2023→2024: 2 · 2024→2025: 2 → average 21.3
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 21.3 × 2.66 = 56.7. Upper limit −12.6, lower limit −126.

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.