Portola Valley Elementary: english

The shaded band is this district'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	83,282	2489.9	− 2432	57.9	× 84 / 430	11.3
4	83,285	2565.2	− 2473	92.2	× 68 / 430	14.6
5	83,286	2577.0	− 2502	75	× 69 / 430	12
6	83,289	2592.3	− 2531	61.3	× 86 / 430	12.3
7	83,290	2637.6	− 2552	85.6	× 63 / 430	12.5
8	83,293	2664.9	− 2567	97.9	× 60 / 430	13.7
Sum, rounded to a whole point						76

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	77,216	2513.6	− 2432	81.6	× 65 / 420	12.6
4	77,218	2548.6	− 2473	75.6	× 74 / 420	13.3
5	77,221	2592.8	− 2502	90.8	× 68 / 420	14.7
6	77,222	2628.3	− 2531	97.3	× 72 / 420	16.7
7	77,224	2654.7	− 2552	102.7	× 80 / 420	19.6
8	77,227	2639.2	− 2567	72.2	× 61 / 420	10.5
Sum, rounded to a whole point						87

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,324	2504.0	− 2432	72	× 74 / 426	12.5
4	79,325	2546.8	− 2473	73.8	× 68 / 426	11.8
5	79,327	2579.8	− 2502	77.8	× 73 / 426	13.3
6	79,329	2613.3	− 2531	82.3	× 57 / 426	11
7	79,332	2645.5	− 2552	93.5	× 71 / 426	15.6
8	79,334	2656.4	− 2567	89.4	× 83 / 426	17.4
Sum, rounded to a whole point						82

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,466	2513.0	− 2432	81	× 63 / 396	12.9
4	79,469	2550.9	− 2473	77.9	× 71 / 396	14
5	79,470	2613.1	− 2502	111.1	× 63 / 396	17.7
6	79,473	2608.1	− 2531	77.1	× 75 / 396	14.6
7	79,475	2646.3	− 2552	94.3	× 53 / 396	12.6
8	79,477	2656.4	− 2567	89.4	× 71 / 396	16
Sum, rounded to a whole point						88

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,986	2504.9	− 2432	72.9	× 67 / 371	13.2
4	79,987	2563.0	− 2473	90	× 64 / 371	15.5
5	79,988	2597.1	− 2502	95.1	× 68 / 371	17.4
6	79,989	2618.1	− 2531	87.1	× 55 / 371	12.9
7	79,990	2641.8	− 2552	89.8	× 68 / 371	16.5
8	79,991	2666.3	− 2567	99.3	× 49 / 371	13.1
Sum, rounded to a whole point						89

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	78,447	2489.8	− 2432	57.8	× 56 / 307	10.5
4	78,448	2537.2	− 2473	64.2	× 44 / 307	9.2
5	78,449	2598.5	− 2502	96.5	× 57 / 307	17.9
6	78,450	2608.5	− 2531	77.5	× 54 / 307	13.6
7	78,451	2650.2	− 2552	98.2	× 49 / 307	15.7
8	78,452	2668.6	− 2567	101.6	× 47 / 307	15.6
Sum, rounded to a whole point						83

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,256	2503.1	− 2432	71.1	× 54 / 311	12.3
4	80,257	2543.9	− 2473	70.9	× 53 / 311	12.1
5	80,258	2593.1	− 2502	91.1	× 51 / 311	14.9
6	80,259	2589.4	− 2531	58.4	× 56 / 311	10.5
7	80,260	2653.5	− 2552	101.5	× 51 / 311	16.6
8	80,261	2657.7	− 2567	90.7	× 46 / 311	13.4
Sum, rounded to a whole point						80

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,218	2530.4	− 2432	98.4	× 52 / 323	15.8
4	80,219	2566.8	− 2473	93.8	× 58 / 323	16.8
5	80,220	2589.2	− 2502	87.2	× 59 / 323	15.9
6	80,221	2609.2	− 2531	78.2	× 52 / 323	12.6
7	80,222	2645.6	− 2552	93.6	× 54 / 323	15.6
8	80,223	2669.0	− 2567	102	× 48 / 323	15.2
Sum, rounded to a whole point						92

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,240	2505.0	− 2432	73	× 51 / 310	12
4	80,241	2561.4	− 2473	88.4	× 48 / 310	13.7
5	80,242	2610.2	− 2502	108.2	× 58 / 310	20.2
6	80,243	2592.1	− 2531	61.1	× 47 / 310	9.3
7	80,244	2677.0	− 2552	125	× 54 / 310	21.8
8	80,245	2659.2	− 2567	92.2	× 52 / 310	15.5
Sum, rounded to a whole point						92

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,904	2521.4	− 2432	89.4	× 61 / 313	17.4
4	79,905	2566.9	− 2473	93.9	× 49 / 313	14.7
5	79,906	2596.6	− 2502	94.6	× 49 / 313	14.8
6	79,907	2617.2	− 2531	86.2	× 51 / 313	14
7	79,908	2636.5	− 2552	84.5	× 49 / 313	13.2
8	79,909	2688.5	− 2567	121.5	× 54 / 313	21
Sum, rounded to a whole point						95

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. 76, 87, 82, 88, 89, 83, 80, 92, 92, 95 → 86.4
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: 5 · 2017→2018: 6 · 2018→2019: 1 · 2019→2021: 6 · 2021→2022: 3 · 2022→2023: 12 · 2023→2024: 0 · 2024→2025: 3 → average 5.2
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 5.2 × 2.66 = 13.8. Upper limit 100.2, lower limit 72.6.

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".

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 — for a district, the total across its schools. From 2014–15, 2015–16, 2016–17, 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.