California Virtual Academy @ Maricopa: 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.

Measured against the grade bars

The state's math 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 81 points under the grade 3 bar. 2355 vs. 2436.
4th The average 4th grader scores 54 points under the grade 3 bar. 2383 vs. 2436. The 4th-grade bar is 2485.
5th The average 5th grader scores 23 points under the grade 3 bar. 2413 vs. 2436. The 5th-grade bar is 2528.
6th The average 6th grader scores 11 points under the grade 3 bar. 2426 vs. 2436. The 6th-grade bar is 2552.
7th The average 7th grader scores 35 points under the grade 4 bar. 2450 vs. 2485. The 7th-grade bar is 2567.
8th The average 8th grader scores just under the grade 4 bar. 2476 vs. 2485. The 8th-grade bar is 2586.
11th The average 11th grader scores 24 points under the grade 5 bar. 2504 vs. 2528. The 11th-grade bar is 2628.

2018 results. "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	17,461	2365.9	− 2436	−70.1	× 120 / 821	−10.2
4	17,464	2417.4	− 2485	−67.6	× 132 / 821	−10.9
5	17,465	2448.9	− 2528	−79.1	× 131 / 821	−12.6
6	17,468	2470.1	− 2552	−81.9	× 123 / 821	−12.3
7	17,469	2496.4	− 2567	−70.6	× 156 / 821	−13.4
8	17,472	2485.4	− 2586	−100.6	× 159 / 821	−19.5
Sum, rounded to a whole point						−79

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	16,479	2368.2	− 2436	−67.8	× 108 / 755	−9.7
4	16,480	2409.2	− 2485	−75.8	× 109 / 755	−10.9
5	16,483	2429.8	− 2528	−98.2	× 112 / 755	−14.6
6	16,484	2447.3	− 2552	−104.7	× 135 / 755	−18.7
7	16,487	2476.6	− 2567	−90.4	× 118 / 755	−14.1
8	16,488	2488.6	− 2586	−97.4	× 173 / 755	−22.3
Sum, rounded to a whole point						−90

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	16,788	2344.8	− 2436	−91.2	× 94 / 777	−11
4	16,790	2401.6	− 2485	−83.4	× 90 / 777	−9.7
5	16,791	2408.4	− 2528	−119.6	× 102 / 777	−15.7
6	16,793	2424.8	− 2552	−127.2	× 112 / 777	−18.3
7	16,796	2479.9	− 2567	−87.1	× 146 / 777	−16.4
8	16,797	2475.0	− 2586	−111	× 129 / 777	−18.4
11	16,799	2515.6	− 2628	−112.4	× 104 / 777	−15
Sum, rounded to a whole point						−105

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	16,807	2354.7	− 2436	−81.3	× 66 / 744	−7.2
4	16,808	2382.5	− 2485	−102.5	× 72 / 744	−9.9
5	16,811	2413.2	− 2528	−114.8	× 91 / 744	−14
6	16,812	2425.5	− 2552	−126.5	× 127 / 744	−21.6
7	16,815	2449.9	− 2567	−117.1	× 152 / 744	−23.9
8	16,816	2476.4	− 2586	−109.6	× 141 / 744	−20.8
11	16,819	2504.0	− 2628	−124	× 95 / 744	−15.8
Sum, rounded to a whole point						−113

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −79, −90, −105, −113 → −96.8
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 11 · 2016→2017: 15 · 2017→2018: 8 → average 11.3
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 11.3 × 2.66 = 30.1. Upper limit −66.7, lower limit −126.9.

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.