Excel Prep Charter - Ie: 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 6.

3rd The average 3rd grader scores 40 points under the grade 3 bar. 2396 vs. 2436.
4th The average 4th grader scores just under the grade 3 bar. 2434 vs. 2436. The 4th-grade bar is 2485.
5th The average 5th grader scores 36 points under the grade 4 bar. 2449 vs. 2485. The 5th-grade bar is 2528.
6th The average 6th grader scores 43 points under the grade 4 bar. 2442 vs. 2485. The 6th-grade bar is 2552.

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	57,457	2338.6	− 2436	−97.4	× 86 / 401	−20.9
4	57,458	2387.9	− 2485	−97.1	× 83 / 401	−20.1
5	57,461	2412.3	− 2528	−115.7	× 64 / 401	−18.5
6	57,462	2454.6	− 2552	−97.4	× 68 / 401	−16.5
7	57,465	2455.1	− 2567	−111.9	× 56 / 401	−15.6
8	57,466	2473.8	− 2586	−112.2	× 44 / 401	−12.3
Sum, rounded to a whole point						−104

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	53,329	2366.9	− 2436	−69.1	× 116 / 376	−21.3
4	53,332	2395.8	− 2485	−89.2	× 100 / 376	−23.7
5	53,334	2433.5	− 2528	−94.5	× 91 / 376	−22.9
6	53,336	2437.4	− 2552	−114.6	× 69 / 376	−21
Sum, rounded to a whole point						−89

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	54,885	2388.6	− 2436	−47.4	× 91 / 349	−12.4
4	54,886	2421.4	− 2485	−63.6	× 106 / 349	−19.3
5	54,888	2409.5	− 2528	−118.5	× 79 / 349	−26.8
6	54,891	2449.2	− 2552	−102.8	× 73 / 349	−21.5
Sum, rounded to a whole point						−80

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	54,978	2395.9	− 2436	−40.1	× 105 / 353	−11.9
4	54,980	2434.4	− 2485	−50.6	× 87 / 353	−12.5
5	54,982	2449.3	− 2528	−78.7	× 99 / 353	−22.1
6	54,984	2442.0	− 2552	−110	× 62 / 353	−19.3
Sum, rounded to a whole point						−66

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −104, −89, −80, −66 → −84.8
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: 9 · 2017→2018: 14 → average 12.7
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 12.7 × 2.66 = 33.8. Upper limit −51, lower limit −118.6.

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.