Portola Junior/Senior High: 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
7	54,992	2513.9	− 2567	−53.1	× 44 / 109	−21.4
8	54,995	2526.6	− 2586	−59.4	× 29 / 109	−15.8
11	54,996	2582.1	− 2628	−45.9	× 36 / 109	−15.2
Sum, rounded to a whole point						−52

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	51,086	2543.1	− 2567	−23.9	× 45 / 117	−9.2
8	51,088	2538.8	− 2586	−47.2	× 39 / 117	−15.7
11	51,089	2618.8	− 2628	−9.2	× 33 / 117	−2.6
Sum, rounded to a whole point						−28

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	52,542	2552.1	− 2567	−14.9	× 49 / 128	−5.7
8	52,544	2547.5	− 2586	−38.5	× 50 / 128	−15
11	52,545	2543.6	− 2628	−84.4	× 29 / 128	−19.1
Sum, rounded to a whole point						−40

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	52,614	2565.8	− 2567	−1.2	× 46 / 123	−0.4
8	52,615	2559.2	− 2586	−26.8	× 45 / 123	−9.8
11	52,618	2562.3	− 2628	−65.7	× 32 / 123	−17.1
Sum, rounded to a whole point						−27

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	52,794	2541.1	− 2567	−25.9	× 50 / 129	−10
8	52,795	2520.7	− 2586	−65.3	× 41 / 129	−20.8
11	52,796	2568.8	− 2628	−59.2	× 38 / 129	−17.4
Sum, rounded to a whole point						−48

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	51,575	2486.9	− 2567	−80.1	× 44 / 124	−28.4
8	51,576	2528.6	− 2586	−57.4	× 47 / 124	−21.8
11	51,577	2557.2	− 2628	−70.8	× 33 / 124	−18.8
Sum, rounded to a whole point						−69

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	52,772	2536.7	− 2567	−30.3	× 46 / 121	−11.5
8	52,773	2481.0	− 2586	−105	× 44 / 121	−38.2
11	52,774	2537.7	− 2628	−90.3	× 31 / 121	−23.1
Sum, rounded to a whole point						−73

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	52,731	2517.8	− 2567	−49.2	× 44 / 139	−15.6
8	52,732	2502.7	− 2586	−83.3	× 47 / 139	−28.2
11	52,733	2486.1	− 2628	−141.9	× 48 / 139	−49
Sum, rounded to a whole point						−93

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	52,561	2485.5	− 2567	−81.5	× 32 / 110	−23.7
8	52,562	2501.1	− 2586	−84.9	× 42 / 110	−32.4
11	52,563	2554.4	− 2628	−73.6	× 36 / 110	−24.1
Sum, rounded to a whole point						−80

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
7	52,321	2490.3	− 2567	−76.7	× 47 / 117	−30.8
8	52,322	2481.7	− 2586	−104.3	× 36 / 117	−32.1
11	52,323	2501.3	− 2628	−126.7	× 34 / 117	−36.8
Sum, rounded to a whole point						−100

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −52, −28, −40, −27, −48, −69, −73, −93, −80, −100 → −61
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 24 · 2016→2017: 12 · 2017→2018: 13 · 2018→2019: 21 · 2019→2021: 21 · 2021→2022: 4 · 2022→2023: 20 · 2023→2024: 13 · 2024→2025: 20 → average 16.4
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 16.4 × 2.66 = 43.6. Upper limit −17.4, lower limit −104.6.

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. From 2014–15, 2015–16, 2016–17, 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.