George K. Porter Middle: english

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	33,073	2512.6	− 2531	−18.4	× 512 / 1572	−6
7	33,076	2527.1	− 2552	−24.9	× 512 / 1572	−8.1
8	33,077	2572.2	− 2567	5.2	× 548 / 1572	1.8
Sum, rounded to a whole point						−12

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	31,287	2515.1	− 2531	−15.9	× 552 / 1580	−5.6
7	31,289	2532.7	− 2552	−19.3	× 514 / 1580	−6.3
8	31,292	2552.4	− 2567	−14.6	× 514 / 1580	−4.7
Sum, rounded to a whole point						−17

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	31,848	2513.5	− 2531	−17.5	× 524 / 1583	−5.8
7	31,851	2538.7	− 2552	−13.3	× 546 / 1583	−4.6
8	31,852	2557.7	− 2567	−9.3	× 513 / 1583	−3
Sum, rounded to a whole point						−13

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	31,886	2528.9	− 2531	−2.1	× 480 / 1513	−0.7
7	31,888	2555.3	− 2552	3.3	× 495 / 1513	1.1
8	31,890	2572.3	− 2567	5.3	× 538 / 1513	1.9
Sum, rounded to a whole point						2

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	32,059	2546.7	− 2531	15.7	× 405 / 1364	4.7
7	32,060	2569.1	− 2552	17.1	× 467 / 1364	5.9
8	32,061	2586.9	− 2567	19.9	× 492 / 1364	7.2
Sum, rounded to a whole point						18

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	32,086	2512.6	− 2531	−18.4	× 294 / 1010	−5.4
7	32,087	2554.8	− 2552	2.8	× 347 / 1010	1
8	32,088	2573.9	− 2567	6.9	× 369 / 1010	2.5
Sum, rounded to a whole point						−2

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	32,145	2532.3	− 2531	1.3	× 321 / 958	0.4
7	32,146	2545.7	− 2552	−6.3	× 292 / 958	−1.9
8	32,147	2577.9	− 2567	10.9	× 345 / 958	3.9
Sum, rounded to a whole point						2

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	32,011	2538.9	− 2531	7.9	× 347 / 972	2.8
7	32,012	2564.6	− 2552	12.6	× 324 / 972	4.2
8	32,013	2571.9	− 2567	4.9	× 301 / 972	1.5
Sum, rounded to a whole point						9

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	31,870	2569.5	− 2531	38.5	× 319 / 973	12.6
7	31,871	2572.9	− 2552	20.9	× 346 / 973	7.4
8	31,872	2597.8	− 2567	30.8	× 308 / 973	9.7
Sum, rounded to a whole point						30

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −12, −17, −13, 2, 18, −2, 2, 9, 30 → 1.9
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 5 · 2016→2017: 4 · 2017→2018: 15 · 2018→2019: 16 · 2019→2022: 20 · 2022→2023: 4 · 2023→2024: 7 · 2024→2025: 21 → average 11.5
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 11.5 × 2.66 = 30.6. Upper limit 32.5, lower limit −28.7.

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.