← All proof trees · WILLIAM M. MEREDITH SCHOOL

1. 1
   What you seeKeystone Algebra I proficiency

   77.8%

   the share of students scoring proficient or advanced on the Keystone Algebra I end-of-course exam.

   vs. peers

   79th percentile

   vs. citywide

   88th percentile

   unit

   percent

   direction

   higher is better

2. 2
   How it was computedvalue = the state's published percentage for the school × subgroup, as-is

   1. Read the state's wide-format datafile: one row per Pennsylvania school, one column per measure × subgroup (e.g. PercentPersistentAttendance_Black).
   2. Keep Philadelphia rows by mapping the state's AUN + Schl codes to the district's ULCS code through the Master School List.
   3. Unpivot each recognized measure × subgroup column into one served cell; state suppression codes ('IS', '--', '*') are stored as suppressed.

   Citywide percentile, reconstructed right now

   Among 43 default-included schools with a value for this metric, year, and subgroup, this school has a higher value than 37. Midrank rule: (37 + 0/2) / (43 − 1) = 0.881.Stored: 0.881. ✓ matches

   How percentiles are computed · How peer groups are chosen

   Peer percentile, reconstructed right now

   Peer group: up to 40 of the demographically nearest schools among Elementary-Middle / catchment / district schools; 14 of 40 peers have a value this year. This school is above 11 of them. Midrank: (11 + 0/2) / (15 − 1) = 0.786; stored 0.786. ✓ matches

   The peers and their values (14)

   Peer school	Value
   ALBERT M. GREENFIELD SCHOOL	89.4%
   PENN ALEXANDER SCHOOL	81.6%
   COPPIN, FANNY JACKSON SCHOOL	81.5%
   GEN. GEORGE A. MCCALL SCHOOL	73.7%
   CHARLES W. HENRY SCHOOL	62.5%
   COOK-WISSAHICKON SCHOOL	50.0%
   STEPHEN DECATUR SCHOOL	37.2%
   HANCOCK DEMONSTRATION SCHOOL	33.3%
   THOMAS HOLME SCHOOL	32.0%
   ROBERT B. POLLOCK SCHOOL	30.0%
   A.L. FITZPATRICK SCHOOL	26.1%
   NORTHEAST COMMUNITY PROPEL ACADEMY	18.9%
   LOUIS H. FARRELL SCHOOL	14.3%
   ETHAN ALLEN SCHOOL	10.5%

   Note: stored percentiles are computed by a batch script after loads; a difference from the live reconstruction means a newer load changed the comparison set and the batch has not been re-run.

   Evidence: metric tree: Keystone Algebra I proficiency

3. 3
   The stored cellThe stored cell

   table

   philly_school_year_metrics

   value

   77.8

   denominator

   null (not published)

   suppressed

   false

   citywide_percentile

   0.8810

   comparison_group_percentile

   0.7857

   source_load_id

   2fdcb9ea-d4af-4a48-a7cf-a8e6166696b3

   Evidence: data model overview

4. 4
   The load that wrote itWritten on 2026-09-08 by futurereadypa_performance.ts

   source id

   futurereadypa_performance_2023-24

   file URL

   https://futurereadypa.org/home/getdatafile?id=49

   SHA-256 of the file read

   89219f7a7ffbc6adc14f54e87f2872ab04ce12a9e0749c448cf54998e4930e90Copy hash

   bytes

   4,861,549

   year covered

   2023-24

   code commit

   c19ea6ec845c65bcc40eb49644be1c7e67b05f25

   To confirm you have the same file: download it from the URL above, then run shasum -a 256 <downloaded file> Copy command — the output should equal the hash above. If the publisher has since replaced the file, the hashes will differ, which is itself useful to know.

   Evidence: loader script · first-fetch findings for this file · source registry

5. 5
   The publisher's fileFuture Ready PA Index datafile, 2023-24

   Pennsylvania Department of Education (Future Ready PA Index). Same structure as the 2024-25 file.

   format

   XLSX (wide)

   join key

   AUN + Schl → ULCS

   landing page

   https://futurereadypa.org/Home/DataFiles

   • Same as 2024-25.
6. 6
   How it was checkedChecks: 1 passed, 1 flagged

   • ✓ passedBase case (district file, 2024-25): 54 of 54 unsuppressed cells match
   • ⚠ flaggedCross-publisher sanity check (state vs district)

   Checked at ±1: 0 mismatches, 0 cells served but absent from the file, 0 in the file but not served (ALL, acct, latest year).

   Evidence: Base case (district file, 2024-25) · Cross-publisher sanity check (state vs district)

7. 7
   Assumptions & caveatsAssumptions and caveats

   • The state's AUN + Schl → ULCS mapping from the 2024-25 Master School List is correct. State rows for schools not in that directory — district schools that closed before 2024-25 — are not loaded, so every year of state data is a survivor-only panel; cyber charters have their own AUNs and are outside the district's directory.
   • Where two directory schools share a state code (a school and its Continuation Academy), the state's single row belongs to the main school (deterministic rule; the full absenteeism QA lists every shared code).

   • Served from both the district's file (district-run schools) and the state's file (all schools); check the load record on a cell to see which.

   Algorithms involved: Reading the state's wide-format datafile, Citywide and peer-group percentiles, Peer groups: 40 nearest neighbors on demographics