Mattole Valley Charter (#159): 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.

Measured against the grade bars

The state's English test uses one scale for every grade, so a score means the same thing in grade 3 as in grade 11.

3rd The average 3rd grader scores just under the grade 3 bar. 2423 vs. 2432.
4th The average 4th grader scores 26 points under the grade 4 bar. 2447 vs. 2473.
5th The average 5th grader scores just under the grade 5 bar. 2494 vs. 2502.
6th The average 6th grader scores 26 points under the grade 5 bar. 2476 vs. 2502. The 6th-grade bar is 2531.
7th The average 7th grader scores just under the grade 7 bar. 2546 vs. 2552.
8th The average 8th grader scores 15 points under the grade 6 bar. 2516 vs. 2531. The 8th-grade bar is 2567.
11th The average 11th grader scores 12 points under the grade 11 bar. 2571 vs. 2583.

2018 results. The English test covers reading, writing, listening and research together. "Meets standard" is the state's mark for being on track for that grade.

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
3	14,375	2404.5	− 2432	−27.5	× 49 / 362	−3.7
4	14,376	2447.6	− 2473	−25.4	× 66 / 362	−4.6
5	14,379	2481.6	− 2502	−20.4	× 39 / 362	−2.2
6	14,380	2524.5	− 2531	−6.5	× 50 / 362	−0.9
7	14,383	2535.1	− 2552	−16.9	× 37 / 362	−1.7
8	14,384	2546.1	− 2567	−20.9	× 34 / 362	−2
11	14,387	2541.8	− 2583	−41.2	× 87 / 362	−9.9
Sum, rounded to a whole point						−25

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	13,396	2434.8	− 2432	2.8	× 46 / 289	0.4
4	13,399	2443.3	− 2473	−29.7	× 32 / 289	−3.3
5	13,400	2517.3	− 2502	15.3	× 52 / 289	2.8
6	13,403	2544.9	− 2531	13.9	× 32 / 289	1.5
7	13,404	2538.0	− 2552	−14	× 33 / 289	−1.6
8	13,406	2546.2	− 2567	−20.8	× 35 / 289	−2.5
11	13,408	2546.0	− 2583	−37	× 59 / 289	−7.6
Sum, rounded to a whole point						−10

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	13,729	2417.2	− 2432	−14.8	× 49 / 291	−2.5
4	13,731	2446.6	− 2473	−26.4	× 56 / 291	−5.1
5	13,733	2483.7	− 2502	−18.3	× 28 / 291	−1.8
6	13,736	2545.5	− 2531	14.5	× 54 / 291	2.7
7	13,737	2487.8	− 2552	−64.2	× 34 / 291	−7.5
8	13,739	2562.4	− 2567	−4.6	× 29 / 291	−0.5
11	13,741	2570.7	− 2583	−12.3	× 41 / 291	−1.7
Sum, rounded to a whole point						−16

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	13,720	2422.9	− 2432	−9.1	× 67 / 355	−1.7
4	13,721	2447.3	− 2473	−25.7	× 55 / 355	−4
5	13,724	2493.6	− 2502	−8.4	× 54 / 355	−1.3
6	13,725	2476.2	− 2531	−54.8	× 29 / 355	−4.5
7	13,728	2546.2	− 2552	−5.8	× 56 / 355	−0.9
8	13,729	2516.2	− 2567	−50.8	× 46 / 355	−6.6
11	13,731	2571.3	− 2583	−11.7	× 48 / 355	−1.6
Sum, rounded to a whole point						−21

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −25, −10, −16, −21 → −18
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 15 · 2016→2017: 6 · 2017→2018: 5 → average 8.7
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 8.7 × 2.66 = 23.1. Upper limit 5.1, lower limit −41.1.

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".

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.