Lydia Romero-Cruz 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
4	52,111	2424.3	− 2485	−60.7	× 124 / 257	−29.3
5	52,113	2432.2	− 2528	−95.8	× 133 / 257	−49.6
Sum, rounded to a whole point						−79

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
4	48,430	2427.2	− 2485	−57.8	× 152 / 275	−31.9
5	48,432	2447.7	− 2528	−80.3	× 123 / 275	−35.9
Sum, rounded to a whole point						−68

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
4	49,750	2442.0	− 2485	−43	× 140 / 280	−21.5
5	49,752	2459.8	− 2528	−68.2	× 140 / 280	−34.1
Sum, rounded to a whole point						−56

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
4	49,764	2423.3	− 2485	−61.7	× 71 / 174	−25.2
5	49,766	2465.7	− 2528	−62.3	× 103 / 174	−36.9
Sum, rounded to a whole point						−62

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
4	49,961	2440.8	− 2485	−44.2	× 69 / 133	−22.9
5	49,962	2468.4	− 2528	−59.6	× 64 / 133	−28.7
Sum, rounded to a whole point						−52

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	48,686	2332.2	− 2436	−103.8	× 19 / 433	−4.6
4	48,687	2365.6	− 2485	−119.4	× 18 / 433	−5
5	48,688	2408.4	− 2528	−119.6	× 18 / 433	−5
6	48,689	2402.4	− 2552	−149.6	× 117 / 433	−40.4
7	48,690	2436.6	− 2567	−130.4	× 115 / 433	−34.6
8	48,691	2432.4	− 2586	−153.6	× 146 / 433	−51.8
Sum, rounded to a whole point						−141

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,865	2344.6	− 2436	−91.4	× 26 / 771	−3.1
4	49,866	2398.8	− 2485	−86.2	× 31 / 771	−3.5
5	49,867	2412.2	− 2528	−115.8	× 21 / 771	−3.2
6	49,868	2379.6	− 2552	−172.4	× 258 / 771	−57.7
7	49,869	2435.8	− 2567	−131.2	× 220 / 771	−37.4
8	49,870	2439.5	− 2586	−146.5	× 215 / 771	−40.9
Sum, rounded to a whole point						−146

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,829	2359.7	− 2436	−76.3	× 35 / 712	−3.8
4	49,830	2409.7	− 2485	−75.3	× 27 / 712	−2.9
5	49,831	2421.1	− 2528	−106.9	× 33 / 712	−5
6	49,832	2409.6	− 2552	−142.4	× 176 / 712	−35.2
7	49,833	2410.1	− 2567	−156.9	× 237 / 712	−52.2
8	49,834	2445.2	− 2586	−140.8	× 204 / 712	−40.3
Sum, rounded to a whole point						−139

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,680	2357.7	− 2436	−78.3	× 45 / 730	−4.8
4	49,681	2405.8	− 2485	−79.2	× 32 / 730	−3.5
5	49,682	2430.9	− 2528	−97.1	× 24 / 730	−3.2
6	49,683	2396.9	− 2552	−155.1	× 203 / 730	−43.1
7	49,684	2418.6	− 2567	−148.4	× 171 / 730	−34.8
8	49,685	2424.7	− 2586	−161.3	× 255 / 730	−56.3
Sum, rounded to a whole point						−146

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,442	2340.1	− 2436	−95.9	× 38 / 663	−5.5
4	49,443	2400.6	− 2485	−84.4	× 46 / 663	−5.9
5	49,444	2429.2	− 2528	−98.8	× 30 / 663	−4.5
6	49,445	2399.5	− 2552	−152.5	× 188 / 663	−43.2
7	49,446	2434.5	− 2567	−132.5	× 194 / 663	−38.8
8	49,447	2451.4	− 2586	−134.6	× 167 / 663	−33.9
Sum, rounded to a whole point						−132

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −79, −68, −56, −62, −52, −141, −146, −139, −146, −132 → −102.1
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: 12 · 2017→2018: 6 · 2018→2019: 10 · 2019→2021: 89 · 2021→2022: 5 · 2022→2023: 7 · 2023→2024: 7 · 2024→2025: 14 → average 17.9
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 17.9 × 2.66 = 47.6. Upper limit −54.5, lower limit −149.7.

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.