Selby Lane Elementary: 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.

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	83,586	2395.2	− 2436	−40.8	× 66 / 418	−6.4
4	83,589	2451.4	− 2485	−33.6	× 73 / 418	−5.9
5	83,590	2443.5	− 2528	−84.5	× 75 / 418	−15.2
6	83,593	2470.8	− 2552	−81.2	× 55 / 418	−10.7
7	83,594	2529.7	− 2567	−37.3	× 73 / 418	−6.5
8	83,597	2534.4	− 2586	−51.6	× 76 / 418	−9.4
Sum, rounded to a whole point						−54

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	77,527	2409.8	− 2436	−26.2	× 54 / 392	−3.6
4	77,529	2438.5	− 2485	−46.5	× 58 / 392	−6.9
5	77,531	2488.3	− 2528	−39.7	× 62 / 392	−6.3
6	77,533	2498.1	− 2552	−53.9	× 84 / 392	−11.6
7	77,534	2493.0	− 2567	−74	× 59 / 392	−11.1
8	77,537	2554.3	− 2586	−31.7	× 75 / 392	−6.1
Sum, rounded to a whole point						−46

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,664	2391.5	− 2436	−44.5	× 70 / 404	−7.7
4	79,666	2449.0	− 2485	−36	× 52 / 404	−4.6
5	79,667	2446.8	− 2528	−81.2	× 54 / 404	−10.9
6	79,670	2522.2	− 2552	−29.8	× 77 / 404	−5.7
7	79,672	2487.3	− 2567	−79.7	× 89 / 404	−17.6
8	79,673	2538.7	− 2586	−47.3	× 62 / 404	−7.3
Sum, rounded to a whole point						−54

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,801	2437.5	− 2436	1.5	× 69 / 431	0.2
4	79,802	2437.8	− 2485	−47.2	× 69 / 431	−7.6
5	79,805	2457.0	− 2528	−71	× 56 / 431	−9.2
6	79,806	2501.6	− 2552	−50.4	× 60 / 431	−7
7	79,809	2523.4	− 2567	−43.6	× 88 / 431	−8.9
8	79,810	2561.1	− 2586	−24.9	× 89 / 431	−5.1
Sum, rounded to a whole point						−38

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,305	2396.6	− 2436	−39.4	× 82 / 411	−7.9
4	80,306	2478.7	− 2485	−6.3	× 63 / 411	−1
5	80,307	2450.2	− 2528	−77.8	× 67 / 411	−12.7
6	80,308	2500.5	− 2552	−51.5	× 55 / 411	−6.9
7	80,309	2485.6	− 2567	−81.4	× 60 / 411	−11.9
8	80,310	2605.1	− 2586	19.1	× 84 / 411	3.9
Sum, rounded to a whole point						−36

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,532	2395.8	− 2436	−40.2	× 87 / 275	−12.7
4	80,533	2440.3	− 2485	−44.7	× 100 / 275	−16.3
5	80,534	2434.7	− 2528	−93.3	× 88 / 275	−29.9
Sum, rounded to a whole point						−59

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,498	2435.1	− 2436	−0.9	× 67 / 240	−0.3
4	80,499	2433.4	− 2485	−51.6	× 81 / 240	−17.4
5	80,500	2464.2	− 2528	−63.8	× 92 / 240	−24.5
Sum, rounded to a whole point						−42

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,512	2412.8	− 2436	−23.2	× 83 / 224	−8.6
4	80,513	2456.3	− 2485	−28.7	× 64 / 224	−8.2
5	80,514	2489.9	− 2528	−38.1	× 77 / 224	−13.1
Sum, rounded to a whole point						−30

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,168	2450.0	− 2436	14	× 87 / 232	5.3
4	80,169	2443.1	− 2485	−41.9	× 83 / 232	−15
5	80,170	2486.2	− 2528	−41.8	× 62 / 232	−11.2
Sum, rounded to a whole point						−21

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −54, −46, −54, −38, −36, −59, −42, −30, −21 → −42.2
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 8 · 2016→2017: 8 · 2017→2018: 16 · 2018→2019: 2 · 2019→2022: 23 · 2022→2023: 17 · 2023→2024: 12 · 2024→2025: 9 → average 11.9
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 11.9 × 2.66 = 31.7. Upper limit −10.5, lower limit −73.9.

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".

Years with no result (no state tests were given in spring 2020) are skipped: the year-to-year change runs from the last year with a result to the next one.

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, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.