Biggs High: math · Schoolio

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
11	4,343	2527.7	− 2628	−100.3	× 26 / 26	−100.3
Sum, rounded to a whole point						−100

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,848	2525.5	− 2628	−102.5	× 27 / 27	−102.5
Sum, rounded to a whole point						−103

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,929	2508.0	− 2628	−120	× 46 / 46	−120
Sum, rounded to a whole point						−120

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,935	2513.9	− 2628	−114.1	× 53 / 53	−114.1
Sum, rounded to a whole point						−114

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,972	2492.8	− 2628	−135.2	× 51 / 51	−135.2
Sum, rounded to a whole point						−135

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,824	2467.9	− 2628	−160.1	× 47 / 47	−160.1
Sum, rounded to a whole point						−160

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,868	2455.2	− 2628	−172.8	× 34 / 34	−172.8
Sum, rounded to a whole point						−173

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,851	2515.5	− 2628	−112.5	× 50 / 50	−112.5
Sum, rounded to a whole point						−113

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,818	2480.9	− 2628	−147.1	× 32 / 32	−147.1
Sum, rounded to a whole point						−147

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
11	3,774	2504.3	− 2628	−123.7	× 39 / 39	−123.7
Sum, rounded to a whole point						−124

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −100, −103, −120, −114, −135, −160, −173, −113, −147, −124 → −128.9
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: 17 · 2017→2018: 6 · 2018→2019: 21 · 2019→2021: 25 · 2021→2022: 13 · 2022→2023: 60 · 2023→2024: 34 · 2024→2025: 23 → average 22.4
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 22.4 × 2.66 = 59.6. Upper limit −69.3, lower limit −188.5.

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.