Black Butte Junior High: 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	90,752	2502.8	− 2552	−49.2	× 25 / 66	−18.6
7	90,753	2513.5	− 2567	−53.5	× 25 / 66	−20.3
8	90,756	2566.4	− 2586	−19.6	× 16 / 66	−4.8
Sum, rounded to a whole point						−44

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	84,232	2503.1	− 2552	−48.9	× 18 / 71	−12.4
7	84,233	2532.6	− 2567	−34.4	× 25 / 71	−12.1
8	84,236	2522.3	− 2586	−63.7	× 28 / 71	−25.1
Sum, rounded to a whole point						−50

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	86,555	2529.4	− 2552	−22.6	× 22 / 68	−7.3
7	86,558	2508.7	− 2567	−58.3	× 21 / 68	−18
8	86,559	2522.2	− 2586	−63.8	× 25 / 68	−23.5
Sum, rounded to a whole point						−49

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	86,780	2458.9	− 2552	−93.1	× 14 / 64	−20.4
7	86,781	2518.7	− 2567	−48.3	× 25 / 64	−18.9
8	86,784	2515.6	− 2586	−70.4	× 25 / 64	−27.5
Sum, rounded to a whole point						−67

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	87,385	2475.0	− 2552	−77	× 22 / 67	−25.3
7	87,386	2517.4	− 2567	−49.6	× 17 / 67	−12.6
8	87,387	2559.9	− 2586	−26.1	× 28 / 67	−10.9
Sum, rounded to a whole point						−49

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	87,722	2497.5	− 2552	−54.5	× 23 / 57	−22
7	87,723	2447.0	− 2567	−120	× 22 / 57	−46.3
8	87,724	2414.8	− 2586	−171.2	× 12 / 57	−36
Sum, rounded to a whole point						−104

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	87,640	2480.7	− 2552	−71.3	× 31 / 75	−29.5
7	87,641	2449.5	− 2567	−117.5	× 21 / 75	−32.9
8	87,642	2492.4	− 2586	−93.6	× 23 / 75	−28.7
Sum, rounded to a whole point						−91

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	87,618	2419.2	− 2552	−132.8	× 28 / 82	−45.3
7	87,619	2466.0	− 2567	−101	× 31 / 82	−38.2
8	87,620	2503.5	− 2586	−82.5	× 23 / 82	−23.1
Sum, rounded to a whole point						−107

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	87,310	2441.5	− 2552	−110.5	× 21 / 82	−28.3
7	87,311	2473.9	− 2567	−93.1	× 28 / 82	−31.8
8	87,312	2495.6	− 2586	−90.4	× 33 / 82	−36.4
Sum, rounded to a whole point						−96

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −44, −50, −49, −67, −49, −104, −91, −107, −96 → −73
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: 1 · 2017→2018: 18 · 2018→2019: 18 · 2019→2022: 55 · 2022→2023: 13 · 2023→2024: 16 · 2024→2025: 11 → average 17.3
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 17.3 × 2.66 = 46. Upper limit −27, lower limit −119.

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.