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	7,741	2384.2	− 2436	−51.8	× 71 / 238	−15.5
4	7,742	2393.5	− 2485	−91.5	× 65 / 238	−25
5	7,745	2411.1	− 2528	−116.9	× 57 / 238	−28
6	7,746	2435.8	− 2552	−116.2	× 45 / 238	−22
Sum, rounded to a whole point						−90

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	6,925	2378.6	− 2436	−57.4	× 62 / 246	−14.5
4	6,926	2404.3	− 2485	−80.7	× 66 / 246	−21.7
5	6,929	2439.7	− 2528	−88.3	× 61 / 246	−21.9
6	6,930	2438.4	− 2552	−113.6	× 57 / 246	−26.3
Sum, rounded to a whole point						−84

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	7,136	2360.0	− 2436	−76	× 43 / 220	−14.9
4	7,138	2404.3	− 2485	−80.7	× 61 / 220	−22.4
5	7,140	2422.5	− 2528	−105.5	× 57 / 220	−27.3
6	7,142	2447.2	− 2552	−104.8	× 59 / 220	−28.1
Sum, rounded to a whole point						−93

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	7,154	2384.8	− 2436	−51.2	× 39 / 198	−10.1
4	7,157	2431.5	− 2485	−53.5	× 44 / 198	−11.9
5	7,158	2422.5	− 2528	−105.5	× 57 / 198	−30.4
6	7,161	2467.0	− 2552	−85	× 58 / 198	−24.9
Sum, rounded to a whole point						−77

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	7,201	2359.4	− 2436	−76.6	× 64 / 203	−24.1
4	7,202	2442.0	− 2485	−43	× 42 / 203	−8.9
5	7,203	2426.2	− 2528	−101.8	× 40 / 203	−20.1
6	7,204	2462.6	− 2552	−89.4	× 57 / 203	−25.1
Sum, rounded to a whole point						−78

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	7,142	2334.7	− 2436	−101.3	× 49 / 211	−23.5
4	7,143	2382.1	− 2485	−102.9	× 54 / 211	−26.3
5	7,144	2421.5	− 2528	−106.5	× 60 / 211	−30.3
6	7,145	2451.3	− 2552	−100.7	× 48 / 211	−22.9
Sum, rounded to a whole point						−103

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	7,130	2347.9	− 2436	−88.1	× 57 / 200	−25.1
4	7,131	2391.0	− 2485	−94	× 53 / 200	−24.9
5	7,132	2385.3	− 2528	−142.7	× 41 / 200	−29.3
6	7,133	2431.7	− 2552	−120.3	× 49 / 200	−29.5
Sum, rounded to a whole point						−109

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	7,077	2358.4	− 2436	−77.6	× 53 / 190	−21.6
4	7,078	2388.5	− 2485	−96.5	× 51 / 190	−25.9
5	7,079	2399.7	− 2528	−128.3	× 50 / 190	−33.8
6	7,080	2390.6	− 2552	−161.4	× 36 / 190	−30.6
Sum, rounded to a whole point						−112

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	7,037	2381.2	− 2436	−54.8	× 50 / 200	−13.7
4	7,038	2402.1	− 2485	−82.9	× 52 / 200	−21.6
5	7,039	2409.0	− 2528	−119	× 48 / 200	−28.6
6	7,040	2416.5	− 2552	−135.5	× 50 / 200	−33.9
Sum, rounded to a whole point						−98

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −90, −84, −93, −77, −78, −103, −109, −112, −98 → −93.8
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 6 · 2016→2017: 9 · 2017→2018: 16 · 2018→2019: 1 · 2019→2022: 25 · 2022→2023: 6 · 2023→2024: 3 · 2024→2025: 14 → average 10
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 10 × 2.66 = 26.6. Upper limit −67.2, lower limit −120.4.

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.