Urban Discovery Academy Charter: 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 8.

3rd The average 3rd grader meets the grade 3 bar. 2462 vs. 2436.
4th The average 4th grader scores just under the grade 4 bar. 2478 vs. 2485.
5th The average 5th grader scores 15 points under the grade 5 bar. 2513 vs. 2528.
6th The average 6th grader scores 22 points under the grade 5 bar. 2506 vs. 2528. The 6th-grade bar is 2552.
7th The average 7th grader scores just under the grade 6 bar. 2548 vs. 2552. The 7th-grade bar is 2567.
8th The average 8th grader scores 13 points under the grade 6 bar. 2539 vs. 2552. The 8th-grade bar is 2586.

2017 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	73,649	2418.7	− 2436	−17.3	× 47 / 235	−3.5
4	73,651	2467.6	− 2485	−17.4	× 52 / 235	−3.9
5	73,653	2534.6	− 2528	6.6	× 49 / 235	1.4
6	73,655	2508.7	− 2552	−43.3	× 42 / 235	−7.7
7	73,657	2523.7	− 2567	−43.3	× 20 / 235	−3.7
8	73,659	2549.9	− 2586	−36.1	× 25 / 235	−3.8
Sum, rounded to a whole point						−21

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	68,328	2453.9	− 2436	17.9	× 48 / 286	3
4	68,331	2492.4	− 2485	7.4	× 56 / 286	1.4
5	68,333	2493.8	− 2528	−34.2	× 54 / 286	−6.5
6	68,334	2523.8	− 2552	−28.2	× 54 / 286	−5.3
7	68,337	2536.3	− 2567	−30.7	× 47 / 286	−5
8	68,339	2526.0	− 2586	−60	× 27 / 286	−5.7
Sum, rounded to a whole point						−18

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	70,146	2462.0	− 2436	26	× 46 / 306	3.9
4	70,147	2478.0	− 2485	−7	× 52 / 306	−1.2
5	70,149	2512.6	− 2528	−15.4	× 53 / 306	−2.7
6	70,152	2505.6	− 2552	−46.4	× 53 / 306	−8
7	70,153	2547.9	− 2567	−19.1	× 54 / 306	−3.4
8	70,155	2538.7	− 2586	−47.3	× 48 / 306	−7.4
Sum, rounded to a whole point						−19

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −21, −18, −19 → −19.3
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 3 · 2016→2017: 1 → average 2
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 2 × 2.66 = 5.3. Upper limit −14, lower limit −24.6.

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.