Tarzana Elementary: english

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	32,257	2374.2	− 2432	−57.8	× 62 / 216	−16.6
4	32,259	2407.1	− 2473	−65.9	× 68 / 216	−20.7
5	32,261	2451.3	− 2502	−50.7	× 86 / 216	−20.2
Sum, rounded to a whole point						−58

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	30,471	2433.5	− 2432	1.5	× 57 / 186	0.5
4	30,473	2431.9	− 2473	−41.1	× 62 / 186	−13.7
5	30,476	2466.1	− 2502	−35.9	× 67 / 186	−12.9
Sum, rounded to a whole point						−26

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	31,036	2409.5	− 2432	−22.5	× 71 / 185	−8.6
4	31,039	2455.2	− 2473	−17.8	× 52 / 185	−5
5	31,041	2442.2	− 2502	−59.8	× 62 / 185	−20
Sum, rounded to a whole point						−34

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	31,083	2375.6	− 2432	−56.4	× 51 / 173	−16.6
4	31,085	2460.6	− 2473	−12.4	× 65 / 173	−4.7
5	31,087	2488.5	− 2502	−13.5	× 57 / 173	−4.4
Sum, rounded to a whole point						−26

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	31,255	2380.9	− 2432	−51.1	× 44 / 155	−14.5
4	31,256	2441.5	− 2473	−31.5	× 43 / 155	−8.7
5	31,257	2484.2	− 2502	−17.8	× 68 / 155	−7.8
Sum, rounded to a whole point						−31

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	31,272	2367.1	− 2432	−64.9	× 48 / 134	−23.2
4	31,273	2412.4	− 2473	−60.6	× 41 / 134	−18.5
5	31,274	2453.6	− 2502	−48.4	× 45 / 134	−16.3
Sum, rounded to a whole point						−58

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	31,329	2397.6	− 2432	−34.4	× 40 / 131	−10.5
4	31,330	2435.7	− 2473	−37.3	× 48 / 131	−13.7
5	31,331	2425.4	− 2502	−76.6	× 43 / 131	−25.1
Sum, rounded to a whole point						−49

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	31,195	2417.2	− 2432	−14.8	× 25 / 107	−3.5
4	31,196	2448.6	− 2473	−24.4	× 34 / 107	−7.8
5	31,197	2463.0	− 2502	−39	× 48 / 107	−17.5
Sum, rounded to a whole point						−29

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	31,054	2427.2	− 2432	−4.8	× 29 / 100	−1.4
4	31,055	2473.9	− 2473	0.9	× 31 / 100	0.3
5	31,056	2482.6	− 2502	−19.4	× 40 / 100	−7.8
Sum, rounded to a whole point						−9

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −58, −26, −34, −26, −31, −58, −49, −29, −9 → −35.6
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 32 · 2016→2017: 8 · 2017→2018: 8 · 2018→2019: 5 · 2019→2022: 27 · 2022→2023: 9 · 2023→2024: 20 · 2024→2025: 20 → average 16.1
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 16.1 × 2.66 = 42.8. Upper limit 7.2, lower limit −78.4.

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.