Lower Lake 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	19,427	2388.8	− 2436	−47.2	× 69 / 440	−7.4
4	19,430	2393.4	− 2485	−91.6	× 76 / 440	−15.8
5	19,431	2437.8	− 2528	−90.2	× 82 / 440	−16.8
6	19,434	2460.0	− 2552	−92	× 62 / 440	−13
7	19,435	2491.5	− 2567	−75.5	× 86 / 440	−14.8
8	19,438	2459.3	− 2586	−126.7	× 65 / 440	−18.7
Sum, rounded to a whole point						−86

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,449	2356.2	− 2436	−79.8	× 73 / 320	−18.2
4	18,451	2387.6	− 2485	−97.4	× 54 / 320	−16.4
5	18,454	2417.5	− 2528	−110.5	× 68 / 320	−23.5
6	18,455	2483.9	− 2552	−68.1	× 60 / 320	−12.8
7	18,458	2477.0	− 2567	−90	× 65 / 320	−18.3
Sum, rounded to a whole point						−89

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,780	2373.3	− 2436	−62.7	× 72 / 312	−14.5
4	18,783	2403.2	− 2485	−81.8	× 63 / 312	−16.5
5	18,784	2428.2	− 2528	−99.8	× 50 / 312	−16
6	18,787	2447.2	− 2552	−104.8	× 64 / 312	−21.5
7	18,788	2506.1	− 2567	−60.9	× 63 / 312	−12.3
Sum, rounded to a whole point						−81

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,800	2368.8	− 2436	−67.2	× 77 / 315	−16.4
4	18,803	2394.3	− 2485	−90.7	× 61 / 315	−17.6
5	18,804	2431.7	− 2528	−96.3	× 62 / 315	−19
6	18,807	2469.0	− 2552	−83	× 50 / 315	−13.2
7	18,808	2508.6	− 2567	−58.4	× 65 / 315	−12.1
Sum, rounded to a whole point						−78

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,947	2387.5	− 2436	−48.5	× 89 / 339	−12.7
4	18,948	2399.9	− 2485	−85.1	× 62 / 339	−15.6
5	18,949	2407.6	− 2528	−120.4	× 64 / 339	−22.7
6	18,950	2476.2	− 2552	−75.8	× 64 / 339	−14.3
7	18,951	2525.5	− 2567	−41.5	× 60 / 339	−7.3
Sum, rounded to a whole point						−73

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,470	2372.5	− 2436	−63.5	× 77 / 316	−15.5
4	18,471	2393.6	− 2485	−91.4	× 79 / 316	−22.9
5	18,472	2405.4	− 2528	−122.6	× 56 / 316	−21.7
6	18,473	2396.5	− 2552	−155.5	× 52 / 316	−25.6
7	18,474	2419.9	− 2567	−147.1	× 52 / 316	−24.2
Sum, rounded to a whole point						−110

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,994	2354.4	− 2436	−81.6	× 89 / 400	−18.2
4	18,995	2395.1	− 2485	−89.9	× 89 / 400	−20
5	18,996	2404.6	− 2528	−123.4	× 94 / 400	−29
6	18,997	2420.8	− 2552	−131.2	× 71 / 400	−23.3
7	18,998	2423.5	− 2567	−143.5	× 57 / 400	−20.4
Sum, rounded to a whole point						−111

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,949	2365.2	− 2436	−70.8	× 96 / 439	−15.5
4	18,950	2388.3	− 2485	−96.7	× 100 / 439	−22
5	18,951	2409.3	− 2528	−118.7	× 92 / 439	−24.9
6	18,952	2431.4	− 2552	−120.6	× 87 / 439	−23.9
7	18,953	2445.0	− 2567	−122	× 64 / 439	−17.8
Sum, rounded to a whole point						−104

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,896	2365.8	− 2436	−70.2	× 84 / 380	−15.5
4	18,897	2380.7	− 2485	−104.3	× 104 / 380	−28.5
5	18,898	2402.8	− 2528	−125.2	× 97 / 380	−32
6	18,899	2440.8	− 2552	−111.2	× 95 / 380	−27.8
Sum, rounded to a whole point						−104

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,891	2350.3	− 2436	−85.7	× 97 / 393	−21.2
4	18,892	2389.3	− 2485	−95.7	× 83 / 393	−20.2
5	18,893	2396.8	− 2528	−131.2	× 111 / 393	−37.1
6	18,894	2408.5	− 2552	−143.5	× 102 / 393	−37.2
Sum, rounded to a whole point						−116

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −86, −89, −81, −78, −73, −110, −111, −104, −104, −116 → −95.2
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 3 · 2016→2017: 8 · 2017→2018: 3 · 2018→2019: 5 · 2019→2021: 37 · 2021→2022: 1 · 2022→2023: 7 · 2023→2024: 0 · 2024→2025: 12 → average 8.4
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 8.4 × 2.66 = 22.3. Upper limit −72.9, lower limit −117.5.

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, 2025–26.