← All proof trees · STRAWBERRY MANSION HIGH SCHOOL

1. 1
   What you seeAttendance ≥90% rate

   33.3%

   the share of a school's students who attended at least 90% of the days they were enrolled, as published by the district. 100 minus this number is the site's chronic-absenteeism proxy. Based on 12 students.

   vs. peers

   35th percentile

   vs. citywide

   8th percentile

   unit

   percent

   direction

   higher is better

2. 2
   How it was computedvalue = published '% with 90%+ Attendance (Yearly)'; denominator = published 'Total Students (Yearly)'

   1. Read the district's school-level attendance CSV.
   2. Keep rows for district-run schools in the directory; map the file's Category/Group columns to subgroups (all students, race/ethnicity, gender). Grade-level rows are not stored.
   3. Store the published percentage and student count; suppressed cells are flagged, not zeroed.

   Citywide percentile, reconstructed right now

   Among 194 default-included schools with a value for this metric, year, and subgroup, this school has a higher value than 16. Midrank rule: (16 + 0/2) / (194 − 1) = 0.083.Stored: 0.083. ✓ 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 High / catchment / district schools; 20 of 20 peers have a value this year. This school is above 7 of them. Midrank: (7 + 0/2) / (21 − 1) = 0.350; stored 0.350. ✓ matches

   The peers and their values (20)

   Peer school	Value
   GEORGE WASHINGTON HIGH SCHOOL	60.4%
   MARTIN L. KING HIGH SCHOOL	60.0%
   BENJAMIN FRANKLIN HIGH SCHOOL	49.6%
   ABRAHAM LINCOLN HIGH SCHOOL	48.3%
   HORACE FURNESS HIGH SCHOOL	47.7%
   SOUTH PHILADELPHIA HIGH SCHOOL	47.4%
   NORTHEAST HIGH SCHOOL	46.0%
   SAMUEL S. FELS HIGH SCHOOL	44.8%
   KENSINGTON HEALTH SCIENCES	43.3%
   OLNEY HIGH SCHOOL	42.6%
   SAYRE HIGH SCHOOL	39.1%
   JOHN BARTRAM HIGH SCHOOL	37.4%
   FRANKFORD HIGH SCHOOL	35.3%
   WEST PHILADELPHIA HIGH SCHOOL	32.1%
   VAUX BIG PICTURE HIGH SCHOOL	30.8%
   ROXBOROUGH HIGH SCHOOL	30.5%
   KENSINGTON CAPA	30.5%
   THOMAS EDISON HIGH SCHOOL	27.8%
   KENSINGTON HIGH SCHOOL	27.1%
   OVERBROOK HIGH SCHOOL	21.1%

   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: Attendance ≥90% rate

3. 3
   The stored cellThe stored cell

   table

   philly_school_year_metrics

   value

   33.33

   denominator

   12

   suppressed

   false

   citywide_percentile

   0.0829

   comparison_group_percentile

   0.3500

   source_load_id

   af82e240-a218-4af8-9ddf-31f8ad10d932

   Evidence: data model overview

4. 4
   The load that wrote itWritten on 2026-06-04 by sdp_attendance_and_suspensions.ts

   source id

   sdp_attendance_90_school

   file URL

   https://cdn.philasd.org/offices/performance/Open_Data/School_Performance/Attendance/Student_Attendance_90_School_20260203.csv

   SHA-256 of the file read

   552bf3bd6d53517b0f72e8b023d40e3fdeafc218abe854e6bd1bf25ac5d01e87Copy hash

   bytes

   1,396,410

   year covered

   —

   code commit

   f75e33137e8166eec3f8b5a4b39463d306ef710c

   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 fileStudent attendance — % with 90%+ attendance, by school and year

   School District of Philadelphia (Performance Office). For each school and year, the number and share of students who attended at least 90% of their enrolled days, for all students and by grade, race/ethnicity, and gender. District-run schools only.

   format

   CSV

   join key

   ULCS Code

   landing page

   https://opendataphilly.org/datasets/sdp-school-performance/

   • District sector only — no charter, cyber, contracted, or alternative schools.
   • Small groups are suppressed; from 2021-22 one of Male/Female is also suppressed wherever Non-Binary is, including at large high schools.
   • Denominator ('Total Students (Yearly)') counts students enrolled at least 10 days at the school; a student enrolled 10+ days at two schools is counted at each (SDP, Student Attendance Patterns in Philadelphia 2017-18 to 2021-22, June 2023). Summed across schools it is a count of student records, not distinct students.
6. 6
   How it was checkedChecks: 3 passed, 1 flagged

   • ✓ passedBase case: 216 of 216 served 2024-25 cells match an independent re-read of the file
   • ✓ passedCompleteness: every source cell is served for directory schools
   • ⚠ flaggedCross-publisher vs the state's Regular Attendance figure for the same schools and attendance year: closely correlated, not interchangeable (median and per-year values in the report)
   • ✓ passedFull QA: every served cell (value and student count), every year and subgroup, matches a re-read of the district file

   Checked at ±0.5: 0 mismatches, 0 cells served but absent from the file, 0 in the file but not served (ALL, n/a, latest year).

   Evidence: Base case · Completeness · Cross-publisher vs the state's Regular Attendance figure for the same schools and attendance year · Full QA

7. 7
   Assumptions & caveatsAssumptions and caveats

   • '90%+ attendance' is read as the complement of chronic absenteeism: attending less than 90% of enrolled days. A student at exactly 90% is in the 90%+ group (and so outside the below-90 share) but chronically absent under the federal 'missed 10% or more' definition; the district does not document rounding at that boundary.
   • Minimum enrollment: 10 days at the school, with transfers attributed to each qualifying school (SDP, June 2023 attendance report).

   • District-run schools only.
   • Schools closed before 2024-25 are absent from the served table (their rows exist in the source file and are included in the working-analysis packet).

   Algorithms involved: Chronic absenteeism as 100 minus the 90%-attendance share, Citywide and peer-group percentiles, Peer groups: 40 nearest neighbors on demographics