Westlake Middle: 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
6	3,052	2426.7	− 2552	−125.3	× 141 / 509	−34.7
7	3,054	2450.5	− 2567	−116.5	× 174 / 509	−39.8
8	3,056	2458.9	− 2586	−127.1	× 194 / 509	−48.4
Sum, rounded to a whole point						−123

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,758	2422.5	− 2552	−129.5	× 129 / 443	−37.7
7	2,761	2433.0	− 2567	−134	× 152 / 443	−46
8	2,763	2451.9	− 2586	−134.1	× 162 / 443	−49
Sum, rounded to a whole point						−133

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,833	2392.2	− 2552	−159.8	× 91 / 374	−38.9
7	2,834	2421.2	− 2567	−145.8	× 134 / 374	−52.2
8	2,836	2422.8	− 2586	−163.2	× 149 / 374	−65
Sum, rounded to a whole point						−156

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,836	2395.7	− 2552	−156.3	× 104 / 345	−47.1
7	2,839	2417.1	− 2567	−149.9	× 103 / 345	−44.8
8	2,840	2423.9	− 2586	−162.1	× 138 / 345	−64.8
Sum, rounded to a whole point						−157

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,858	2378.6	− 2552	−173.4	× 91 / 318	−49.6
7	2,859	2395.7	− 2567	−171.3	× 115 / 318	−61.9
8	2,860	2415.4	− 2586	−170.6	× 112 / 318	−60.1
Sum, rounded to a whole point						−172

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,756	2392.9	− 2552	−159.1	× 79 / 232	−54.2
7	2,757	2423.5	− 2567	−143.5	× 80 / 232	−49.5
8	2,758	2445.3	− 2586	−140.7	× 73 / 232	−44.3
Sum, rounded to a whole point						−148

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,696	2392.5	− 2552	−159.5	× 89 / 251	−56.6
7	2,697	2401.3	− 2567	−165.7	× 86 / 251	−56.8
8	2,698	2407.3	− 2586	−178.7	× 76 / 251	−54.1
Sum, rounded to a whole point						−167

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,660	2383.1	− 2552	−168.9	× 94 / 264	−60.1
7	2,661	2411.1	− 2567	−155.9	× 85 / 264	−50.2
8	2,662	2404.0	− 2586	−182	× 85 / 264	−58.6
Sum, rounded to a whole point						−169

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	2,636	2410.6	− 2552	−141.4	× 95 / 267	−50.3
7	2,637	2425.0	− 2567	−142	× 86 / 267	−45.7
8	2,638	2440.9	− 2586	−145.1	× 86 / 267	−46.7
Sum, rounded to a whole point						−143

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −123, −133, −156, −157, −172, −148, −167, −169, −143 → −152
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 10 · 2016→2017: 23 · 2017→2018: 1 · 2018→2019: 15 · 2019→2022: 24 · 2022→2023: 19 · 2023→2024: 2 · 2024→2025: 26 → average 15
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 15 × 2.66 = 39.9. Upper limit −112.1, lower limit −191.9.

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.