Stanislaus County Institute Of Learning: 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
7	96,233	2396.0	− 2567	−171	× 31 / 98	−54.1
8	96,234	2400.9	− 2586	−185.1	× 53 / 98	−100.1
11	96,237	2418.6	− 2628	−209.4	× 14 / 98	−29.9
Sum, rounded to a whole point						−184

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	89,261	2402.9	− 2567	−164.1	× 36 / 98	−60.3
8	89,263	2398.2	− 2586	−187.8	× 32 / 98	−61.3
11	89,266	2422.8	− 2628	−205.2	× 30 / 98	−62.8
Sum, rounded to a whole point						−184

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	91,851	2368.2	− 2552	−183.8	× 13 / 75	−31.9
7	91,853	2397.3	− 2567	−169.7	× 26 / 75	−58.8
8	91,854	2392.4	− 2586	−193.6	× 36 / 75	−92.9
Sum, rounded to a whole point						−184

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
8	92,045	2397.9	− 2586	−188.1	× 49 / 66	−139.7
11	92,048	2460.4	− 2628	−167.6	× 17 / 66	−43.2
Sum, rounded to a whole point						−183

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	92,689	2409.7	− 2552	−142.3	× 12 / 42	−40.7
7	92,690	2436.7	− 2567	−130.3	× 15 / 42	−46.5
8	92,691	2425.9	− 2586	−160.1	× 15 / 42	−57.2
Sum, rounded to a whole point						−144

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	90,721	2429.3	− 2567	−137.7	× 12 / 38	−43.5
8	90,722	2424.0	− 2586	−162	× 26 / 38	−110.8
Sum, rounded to a whole point						−154

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	92,932	2351.9	− 2552	−200.1	× 14 / 83	−33.8
7	92,933	2375.0	− 2567	−192	× 28 / 83	−64.8
8	92,934	2399.0	− 2586	−187	× 22 / 83	−49.6
11	92,935	2425.7	− 2628	−202.3	× 19 / 83	−46.3
Sum, rounded to a whole point						−194

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
8	92,836	2382.8	− 2586	−203.2	× 27 / 43	−127.6
11	92,837	2391.4	− 2628	−236.6	× 16 / 43	−88
Sum, rounded to a whole point						−216

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −184, −184, −184, −183, −144, −154, −194, −216 → −180.4
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 0 · 2016→2017: 0 · 2017→2018: 1 · 2018→2019: 39 · 2019→2021: 10 · 2021→2022: 40 · 2022→2023: 22 → average 16
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 16 × 2.66 = 42.6. Upper limit −137.8, lower limit −223.

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.