Cross-publisher (iii-b) — PSSA ELA aggregate

SDP PSSA file vs Future Ready PA Index file. NB: SDP's PSSA all-grades

(grades 3-8 aggregate) and Future Ready's Keystone Literature (HS) are

DIFFERENT exams measuring ELA at different grade levels — they shouldn't

agree numerically, only correlate. This file establishes the (iii-b) wiring

and reports the cross-publisher pair distribution; a tighter cross-check

would use FRPI's per-grade PSSA columns if/when they're added.

Summary

{
  "n_pairs": 169,
  "mean": 0.218,
  "median": 0.03,
  "stdev": 1.239,
  "min": -3.93,
  "max": 14.48,
  "n_within_1pp": 159,
  "n_within_5pp": 168
}

Largest 20 absolute deltas

8780 2024-25: SDP=23.08 FRPI=8.60 Δ=+14.48
8360 2024-25: SDP=30.47 FRPI=26.40 Δ=+4.07
6460 2024-25: SDP=60.27 FRPI=64.20 Δ=-3.93
2680 2024-25: SDP=68.79 FRPI=66.40 Δ=+2.39
4030 2024-25: SDP=90.67 FRPI=88.80 Δ=+1.87
6380 2024-25: SDP=50.81 FRPI=49.20 Δ=+1.61
2140 2024-25: SDP=90.85 FRPI=92.20 Δ=-1.35
2480 2024-25: SDP=50.27 FRPI=49.00 Δ=+1.27
2520 2024-25: SDP=70.54 FRPI=69.30 Δ=+1.24
6400 2024-25: SDP=6.90 FRPI=8.10 Δ=-1.20
6390 2024-25: SDP=14.07 FRPI=13.10 Δ=+0.97
4520 2024-25: SDP=16.02 FRPI=15.20 Δ=+0.82
5590 2024-25: SDP=22.00 FRPI=21.20 Δ=+0.80
7430 2024-25: SDP=15.38 FRPI=14.60 Δ=+0.78
1130 2024-25: SDP=12.02 FRPI=11.40 Δ=+0.62
5320 2024-25: SDP=14.01 FRPI=13.40 Δ=+0.61
8120 2024-25: SDP=31.09 FRPI=30.50 Δ=+0.59
2630 2024-25: SDP=42.98 FRPI=42.40 Δ=+0.58
4350 2024-25: SDP=7.35 FRPI=6.80 Δ=+0.55
6450 2024-25: SDP=58.78 FRPI=58.30 Δ=+0.48