Twin Lakes 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	35,093	2410.9	− 2436	−25.1	× 59 / 239	−6.2
4	35,096	2419.0	− 2485	−66	× 51 / 239	−14.1
5	35,097	2432.7	− 2528	−95.3	× 58 / 239	−23.1
6	35,100	2487.6	− 2552	−64.4	× 71 / 239	−19.1
Sum, rounded to a whole point						−63

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	32,771	2404.2	− 2436	−31.8	× 77 / 241	−10.2
4	32,773	2424.3	− 2485	−60.7	× 56 / 241	−14.1
5	32,775	2456.8	− 2528	−71.2	× 53 / 241	−15.7
6	32,778	2487.8	− 2552	−64.2	× 55 / 241	−14.7
Sum, rounded to a whole point						−55

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,350	2430.2	− 2436	−5.8	× 44 / 213	−1.2
4	33,352	2439.1	− 2485	−45.9	× 68 / 213	−14.7
5	33,353	2453.0	− 2528	−75	× 50 / 213	−17.6
6	33,356	2496.8	− 2552	−55.2	× 51 / 213	−13.2
Sum, rounded to a whole point						−47

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,369	2419.6	− 2436	−16.4	× 65 / 229	−4.7
4	33,371	2426.6	− 2485	−58.4	× 45 / 229	−11.5
5	33,373	2462.3	− 2528	−65.7	× 66 / 229	−18.9
6	33,375	2490.7	− 2552	−61.3	× 53 / 229	−14.2
Sum, rounded to a whole point						−49

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,542	2410.0	− 2436	−26	× 43 / 196	−5.7
4	33,543	2430.9	− 2485	−54.1	× 61 / 196	−16.8
5	33,544	2478.0	− 2528	−50	× 40 / 196	−10.2
6	33,545	2525.8	− 2552	−26.2	× 52 / 196	−7
Sum, rounded to a whole point						−40

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,479	2362.4	− 2436	−73.6	× 49 / 642	−5.6
4	33,480	2418.4	− 2485	−66.6	× 53 / 642	−5.5
5	33,481	2422.6	− 2528	−105.4	× 55 / 642	−9
6	33,482	2471.2	− 2552	−80.8	× 87 / 642	−10.9
7	33,483	2454.6	− 2567	−112.4	× 186 / 642	−32.6
8	33,484	2461.6	− 2586	−124.4	× 212 / 642	−41.1
Sum, rounded to a whole point						−105

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,530	2397.7	− 2436	−38.3	× 40 / 586	−2.6
4	33,531	2431.7	− 2485	−53.3	× 69 / 586	−6.3
5	33,532	2416.2	− 2528	−111.8	× 73 / 586	−13.9
6	33,533	2504.3	− 2552	−47.7	× 80 / 586	−6.5
7	33,534	2448.7	− 2567	−118.3	× 157 / 586	−31.7
8	33,535	2455.6	− 2586	−130.4	× 167 / 586	−37.2
Sum, rounded to a whole point						−98

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,390	2386.0	− 2436	−50	× 47 / 550	−4.3
4	33,391	2439.3	− 2485	−45.7	× 59 / 550	−4.9
5	33,392	2436.5	− 2528	−91.5	× 71 / 550	−11.8
6	33,393	2403.7	− 2552	−148.3	× 70 / 550	−18.9
7	33,394	2461.0	− 2567	−106	× 164 / 550	−31.6
8	33,395	2437.6	− 2586	−148.4	× 139 / 550	−37.5
Sum, rounded to a whole point						−109

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	33,251	2377.3	− 2436	−58.7	× 23 / 491	−2.7
4	33,252	2413.2	− 2485	−71.8	× 64 / 491	−9.4
5	33,253	2493.3	− 2528	−34.7	× 56 / 491	−4
6	33,254	2454.2	− 2552	−97.8	× 64 / 491	−12.7
7	33,255	2432.5	− 2567	−134.5	× 121 / 491	−33.1
8	33,256	2488.5	− 2586	−97.5	× 163 / 491	−32.4
Sum, rounded to a whole point						−94

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −63, −55, −47, −49, −40, −105, −98, −109, −94 → −73.3
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: 2 · 2018→2019: 9 · 2019→2022: 65 · 2022→2023: 7 · 2023→2024: 11 · 2024→2025: 15 → average 15.6
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 15.6 × 2.66 = 41.5. Upper limit −31.8, lower limit −114.8.

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.