Los Angeles County Special Education: 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 3 bar

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.

4th The average 4th grader scores 76 points under the grade 3 bar. 2361 vs. 2436. The 4th-grade bar is 2485.
5th The average 5th grader scores 107 points under the grade 3 bar. 2330 vs. 2436. The 5th-grade bar is 2528.
6th The average 6th grader scores 114 points under the grade 3 bar. 2323 vs. 2436. The 6th-grade bar is 2552.
7th The average 7th grader scores 34 points under the grade 3 bar. 2402 vs. 2436. The 7th-grade bar is 2567.
8th The average 8th grader scores 38 points under the grade 3 bar. 2398 vs. 2436. The 8th-grade bar is 2586.
11th The average 11th grader scores just under the grade 3 bar. 2431 vs. 2436. 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	20,309	2326.2	− 2436	−109.8	× 14 / 89	−17.3
4	20,312	2349.0	− 2485	−136	× 13 / 89	−19.9
5	20,313	2373.7	− 2528	−154.3	× 10 / 89	−17.3
6	20,316	2322.3	− 2552	−229.7	× 14 / 89	−36.1
7	20,317	2348.8	− 2567	−218.2	× 11 / 89	−27
8	20,320	2381.1	− 2586	−204.9	× 11 / 89	−25.3
11	20,321	2444.7	− 2628	−183.3	× 16 / 89	−33
Sum, rounded to a whole point						−176

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	19,281	2296.6	− 2436	−139.4	× 9 / 104	−12.1
4	19,283	2328.2	− 2485	−156.8	× 11 / 104	−16.6
5	19,286	2367.7	− 2528	−160.3	× 13 / 104	−20
6	19,287	2384.2	− 2552	−167.8	× 17 / 104	−27.4
7	19,290	2336.0	− 2567	−231	× 25 / 104	−55.5
8	19,292	2368.1	− 2586	−217.9	× 16 / 104	−33.5
11	19,293	2450.2	− 2628	−177.8	× 13 / 104	−22.2
Sum, rounded to a whole point						−187

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	19,589	2273.7	− 2436	−162.3	× 14 / 60	−37.9
7	19,598	2400.1	− 2567	−166.9	× 14 / 60	−38.9
8	19,599	2365.1	− 2586	−220.9	× 14 / 60	−51.5
11	19,602	2444.4	− 2628	−183.6	× 18 / 60	−55.1
Sum, rounded to a whole point						−183

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
4	19,579	2360.5	− 2485	−124.5	× 14 / 80	−21.8
5	19,581	2329.5	− 2528	−198.5	× 11 / 80	−27.3
6	19,583	2322.5	− 2552	−229.5	× 16 / 80	−45.9
7	19,585	2401.7	− 2567	−165.3	× 11 / 80	−22.7
8	19,587	2398.1	− 2586	−187.9	× 14 / 80	−32.9
11	19,589	2431.1	− 2628	−196.9	× 14 / 80	−34.5
Sum, rounded to a whole point						−185

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −176, −187, −183, −185 → −182.8
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: 4 · 2017→2018: 2 → average 5.7
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 5.7 × 2.66 = 15.2. Upper limit −167.6, lower limit −198.

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.