Alpha: Cornerstone Academy Preparatory: 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 8.

3rd The average 3rd grader meets the grade 3 bar. 2501 vs. 2432.
4th The average 4th grader meets the grade 4 bar. 2566 vs. 2473.
5th The average 5th grader meets the grade 5 bar. 2541 vs. 2502.
6th The average 6th grader meets the grade 6 bar. 2571 vs. 2531.
7th The average 7th grader meets the grade 7 bar. 2612 vs. 2552.
8th The average 8th grader meets the grade 8 bar. 2624 vs. 2567.

2019 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	87,169	2466.3	− 2432	34.3	× 84 / 200	14.4
4	87,172	2506.3	− 2473	33.3	× 87 / 200	14.5
5	87,173	2538.0	− 2502	36	× 29 / 200	5.2
Sum, rounded to a whole point						34

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,898	2474.0	− 2432	42	× 58 / 246	9.9
4	80,900	2513.9	− 2473	40.9	× 87 / 246	14.5
5	80,901	2526.1	− 2502	24.1	× 75 / 246	7.3
6	80,903	2572.7	− 2531	41.7	× 26 / 246	4.4
Sum, rounded to a whole point						36

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	83,125	2491.2	− 2432	59.2	× 86 / 269	18.9
4	83,127	2534.1	− 2473	61.1	× 56 / 269	12.7
5	83,129	2516.7	− 2502	14.7	× 60 / 269	3.3
6	83,132	2537.7	− 2531	6.7	× 67 / 269	1.7
Sum, rounded to a whole point						37

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	83,342	2498.7	− 2432	66.7	× 59 / 327	12
4	83,344	2552.6	− 2473	79.6	× 89 / 327	21.7
5	83,346	2515.2	− 2502	13.2	× 62 / 327	2.5
6	83,348	2563.7	− 2531	32.7	× 63 / 327	6.3
7	83,350	2552.6	− 2552	0.6	× 54 / 327	0.1
Sum, rounded to a whole point						43

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	83,951	2501.1	− 2432	69.1	× 58 / 359	11.2
4	83,952	2566.0	− 2473	93	× 60 / 359	15.5
5	83,953	2540.9	− 2502	38.9	× 72 / 359	7.8
6	83,954	2571.3	− 2531	40.3	× 66 / 359	7.4
7	83,955	2611.6	− 2552	59.6	× 53 / 359	8.8
8	83,956	2624.3	− 2567	57.3	× 50 / 359	8
Sum, rounded to a whole point						59

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. 34, 36, 37, 43, 59 → 41.8
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 2 · 2016→2017: 1 · 2017→2018: 6 · 2018→2019: 16 → average 6.3
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 6.3 × 2.66 = 16.8. Upper limit 58.6, lower limit 25.

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, 2018–19.