When Graph-JEPA Learns the Wrong Thing: Diagnosing and Repairing Category-Conditional Collapse
Authors: Gollam Rabby, Sören Auer
Organizations: L3S Research Centre, Leibniz University Hannover, Hannover, Germany · TIB Leibniz Information Centre for Science and Technology, Hannover, Germany
Joint-embedding predictive architectures are selected almost universally by linear probing and effective rank. We report a case where both read healthily while the representation carries zero usable instance information. We repair it, and a second failure appears: the repaired metric saturates on a target carrying no structural information. Our corpus is a scientific-reasoning graph over 57,903 articles, each a subgraph. A Graph-JEPA predicts one masked aspect from a subgraph's remaining aspects, attaining linear-probe accuracy 0.871 and effective rank 18-47, yet retrieval recovers 0.00 of 14.4 bits (MRR 1.9e-4 vs chance 1.99e-4, p=0.98). Three upper bounds on the same pool and code recover nearly everything (+14.28, +14.34, +14.22 bits), ruling out corpus, masking, pool, and metric as causes. We trace this to variance allocation - frozen inputs place 86.05% of variance on subgraph identity and 0.40% on aspect identity, while trained latents place 0.39% and 99.61%. This is a property of the objective's optimum: the degenerate solution is a global minimum of the coupled predictor/EMA-target objective, present already at init. A repaired configuration reaches 14.377 of 14.379 bits, above the 13.865-bit oracle; reverting the loss to regression drops it to 0.307 bits, confirming it. Yet the repair licenses nothing about reasoning: the target is reducible, since intra-subgraph edges are a deterministic function of node census. The oracle reaches 96.4% of the ceiling, and our largest effect is the learning-rate schedule, not architecture. Bits and a reasoning probe show no relation across ten cells. A data-derived target fails a quality gate - 25.96% of nodes are duplicate placeholders, and the rest is more generic than supporting evidence. Rank, probes, and metrics can all saturate on an unsupportive evaluation. We release a harness with a reducibility audit and target gate.
Figures & tables
Figure 1: Neither standard health check predicts retrieval, and the null is exact. (left) Pooled effective rank spans 1.2 – 300 across all trained configurations and the ceilings; every trained point lies on the chance line and the ceilings lie ∼14 bits above it. (centre) Probe accuracy spans 0.57 – 0.97 with no corresponding movement; the vertical spread is sampling noise around chance. (right) Cumulative distribution of the gold rank: baseline, centred baseline, best encoder and best fix are indistinguishable from the uniform-random curve (dotted) over the entire range, while the ceiling reaches ≈0.6 at rank 1 . Not a shifted distribution, the same distribution.
Figure 2: Pipeline and diagnosis. (1) Graph construction over 57,903 papers with typed reasoning nodes and edges. (2) Patch extraction; method and result are exact singletons. (3) Frozen sentence features feed a heterogeneous GNN trained with a JEPA objective; we sweep target geometry, aggregator, loss, target frame, structural cue, and regularisation. (4) Both standard health checks pass while retrieval recovers zero bits. Three ceilings show the signal is present, the variance allocation shows where it goes, and Sec. 9 shows that repairing it saturates a reducible target.
Figure 3: From the global reasoning graph to a paper-local target patch. (a) The heterogeneous graph; an extraction window selects one paper and its incident reasoning nodes. (b) The extracted subgraph, a paper node joined by typed edges to its claim, method and result nodes. Note that every edge shown is present for every paper possessing the endpoint node types, which is the content of Prop. 5 .
#
Intervention
rnode
rcand
rquery
B
Diagnosis
0
mean pool, cosine target (baseline)
18.3
18.1
1.9
0.00
p=0.98 : chance
1
+ target VICReg
—
—
—
0.00
no effect
2
infonce , in-batch negatives
—
—
—
0.00
no effect
3
sum / deepsets / attn pooling
—
—
—
0.00
no effect
4
+ input whitening (instance var. ×25 )
—
—
—
0.00
rank ↑ , B flat
5
retrieval frame: centre / rm-top k / ZCA
—
—
—
0.4
0.4 bits on 14.4 bits
Table 1: The diagnostic ladder ( 57,903 set, Protocol R, full pool). B is bits recovered of Bmax=14.379 (Eq. 4 ); 0 is exactly chance. rcand,rquery are the effective ranks of the candidate bank and of the model’s predictions . Rung 7 is the decisive control; rungs 8–10 are the ceilings of Sec. 6 ; rung 11 is the repaired configuration of Sec. 9 , included here so the whole trajectory is in one place. Per-rung detail: App. A13 .
K
Bmax
bm25
bm25-no-ov
oracle
p1
2
0.862
+0.860
+0.850
+0.840
+0.830
10
2.295
+2.284
+2.276
+2.260
+2.240
100
5.262
+5.240
+5.213
+5.198
+5.167
1000
8.531
+8.501
+8.445
+8.455
+8.421
full
14.385
+14.335
+14.250
+14.281
+14.220
full pool, % of Bmax
99.7%
99.1%
99.3%
98.9%
Table 2: Bits recovered against pool difficulty ( 58,145 set). Hard pools of size K are the K nearest within-category neighbours of the gold item, so difficulty increases downward; the pool has N=K+1 items and Bmax=N1log2N! (Eq. 4 ), which lies 1.4427 bits below the index entropy log2N . Vector systems use 4,000 queries, lexical systems a nested 2,000 subsample. All four systems are within 1.2% of the ceiling at every rung; the baseline Graph-JEPA recovers 0.0% and the repaired configuration of Sec. 9 recovers 100.0% .
Variance attributable to
frozen inputs (block B)
frozen inputs (block A)
trained latents (block A)
inputs, de-templated (block B)
aspect identity ( ρasp )
0.40%
-
99.61%
0.0000
paper identity ( ρpap )
86.05%
-
0.39%
—
bits recovered on this representation
+14.281 ( oracle )
13.865 ( oracle )
0.00 (trained)
+14.28
% of the matching Bmax
99.3%
96.4%
0.0%
99.3%
Table 3: The variance allocation. Share of total variance attributable to aspect identity and to paper identity. Columns 1 and 4 are block B (MPNet- 768 ); columns 2 and 3 are block A (MiniLM- 384 ), i.e. the same encoder that produced the trained latents, so the central comparison is within one feature space and the cross-encoder pair is retained only for continuity with the three ceilings. The two groupings are separate one-way decompositions and need not sum to 100% .
aspect share ρ
0.0040
0.9
0.99
0.9961
0.999
0.9999
MRR
1.000
0.893
0.107
0.0171
0.0043
0.0014
B
+12.845
+12.200
+3.833
+1.80
+0.843
+0.266
bits lost
0.000
0.645
9.012
11.045
12.002
12.579
% of Bmax lost
0.0%
5.0%
70.2%
86%
93.4%
97.9%
Table 4: Phase analysis at the measured operating point , at κ^=0.942 and ε^=1.515 , bank size 20,000 so Bmax=12.845 (Eq. 4 ). The trained representation’s measured share ( 99.61% ) predicts the loss of 11.045 of 12.845 bits; the inputs’ share ( 0.40% ) predicts no loss, which is what the three controls observe. Bits lost is 12.845−B and is monotone in ρ by construction. Critical share ρ⋆=0.99999 ( 1−ρ⋆=5.1×10−6 ); removing κ^ or ε^ at ρ=0.9961 moves MRR by <0.004 .
step
ρpap
ρasp
rquery
B
20 k (final)
0.39%
99.61%
1.9
0.00
Table 5: Variance allocation over training (block A, within one encoder, B against Bmax=14.379 ). One forward pass per checkpoint; ρpap and ρasp are the same one-way decompositions as Table 3 , and rquery is the effective rank of the model’s predictions. Step 0 is the randomly initialised encoder before any gradient step.
Config
loss
steps
B
A1
Reading
raw-skip gate
nce
6k
14.379
0.875
gate →0.3886 : encoder used
center :1
nce
3k
14.379
0.963
center :0, main
nce
20k
14.377±0.002
0.753±0.010
3 seeds
center :0, aspect cue
nce
6k
14.376
0.800
center :0, inductive
nce
6k
14.376
0.769
transduction gap +0.001
center :0
nce
3k
14.359
0.862
Table 6: Eleven cells at matched schedule (block C; all share the graph cache, seed and evaluation; B against Bmax=14.379 ; A1 is a held-out reasoning probe with a pre-registered void line at 0.70 , defined in App. A16 ). The reg row is the decisive single-variable result: only the loss differs from the center:0 / nce / 3 k row. Bits span 11.808−14.379 and A1 spans 0.711−0.985 at Spearman ρ=−0.24 ( n=10 , not significant), so the two metrics show no reliable relationship—this paper’s thesis restated on the repaired model. We claim no trade-off and no direction.
Gate / condition
Measured
Threshold
Verdict
G1 exact-duplicate share of challenged_by
25.96%
≤20%
FAIL
G1b genericness gap (challenge − support)
+0.2377
≤0.15
FAIL
G0 census, challenged_by edges
121,516
≥2,000
pass
implies duplicate share
0.00%
≤20%
pass
paper-identity leak (claim- vs paper-grouped)
+0.0003
—
absent
shuffled-label control
0.4975
≈0.500
pass
Table 7: The data-derived target and its pre-registered gates (block C, 3 seeds, paper-grouped splits). Upper: the gates, with thresholds fixed before measurement. Lower: the probe conditions, which we report even though the gates failed, because two of them are independently informative. Every threshold appears in App. A10 .
Appendix figures & tables37 assets
Supplementary material from the paper’s appendix.
Appendix
Claim
Value
Source
Trained retrieval is indistinguishable from chance
0.00 bits, p=0.98
Table 1 , rung 0
Chance level
1.99×10−4 (MRR), 0 bits
Sec. 3 , Eq. 3
Recoverable ceiling, block A / B
14.379 / 14.385 bits
Eq. 4
Linear probe succeeds
0.871
Table 28
Candidate bank is healthy
18.1 , DC 37.6
Table 1
Query bank is degenerate
1.9 , DC 162.2
Table 1
Appendix
Table 8: Each quantitative claim in the abstract and introduction, its value, and the table or figure that establishes it. Every value appears exactly once as a macro in the source, so prose and tables cannot diverge.
Table 9: Which run, corpus subset and sentence encoder produced each block. We keep these separate rather than pooling them, because the blocks measure different objects and the distinction carries the central results of Secs. 7 and 9 .
Symbol
Code name
Meaning
rnode ( /128 )
node_rk
effective rank of node latents
rpool ( /128 )
pool_rk
effective rank of pooled patch vectors
rcand ( /128 )
cand_erank
effective rank of the candidate bank
rquery ( /128 )
query_eff_rank
effective rank of the model’s predictions
DCratio
dc_ratio
∥μ∥/E∥x−μ∥
DCenergy
dc_energy
∥μ∥2/(∥μ∥2+E∥x−μ∥2)
Appendix
Table 10: All effective ranks use Eq. 5 on mean-centred matrices. The distinction between rcand and rquery is central: the former is what standard practice measures, the latter is where the failure lives.
Node type
count
Edge type
count
census-determined?
paper
57,903
(paper, has_claim, claim)
251,938
yes ( =∣ claim ∣ )
claim
251,938
(paper, has_method, method)
57,903
yes ( =∣ paper ∣ )
method
57,903
(paper, has_result, result)
57,903
yes ( =∣ paper ∣ )
result
57,903
(method, produces, result)
57,903
yes ( =∣ paper ∣ )
evidence
373,438
(result, grounds, claim)
251,938
yes ( =∣ claim ∣ )
implication
251,938
(claim, supported_by, evidence)
251,922
no (data-derived)
Appendix
Table 11: Heterogeneous graph statistics ( 57,903 maskable papers). The right-hand column is the reducibility audit of Sec. 9 : a relation whose cardinality equals an endpoint type’s node count is a deterministic function of the census and carries zero information.
Dissociation across 20 cells
probe 0.755 – 0.960 , rpool1.8 – 13.9
Table 29
Anchor dim. 2→128 , rtgt flat
1.6 – 2.0
Table 30
Repair reaches near-ceiling
14.377 bits ( 100.0% )
Table 6
Loss is the lever (one variable)
14.359→0.307 ( 14.05 )
Table 6
Target-frame effect, matched budget
+0.071 bits
Table 20
Schedule effect, matched steps
+1.337 bits
Table 20
Bits and A1 show no reliable relation
ρ=−0.24 , n=10
Table 6
Appendix
Table 12: Per-aspect membership and untrained in-degree. The singleton rows are what make the pooling control decisive.
Table 13: Which run, corpus subset and sentence encoder produced each block. We keep these separate rather than pooling them, because the blocks measure different objects and the distinction carries the central results of Secs. 7 and 9 .
Symbol
Code name
Meaning
rnode ( /128 )
node_rk
effective rank of node latents
rpool ( /128 )
pool_rk
effective rank of pooled patch vectors
rcand ( /128 )
cand_erank
effective rank of the candidate bank
rquery ( /128 )
query_eff_rank
effective rank of the model’s predictions
DCratio
dc_ratio
∥μ∥/E∥x−μ∥
DCenergy
dc_energy
∥μ∥2/(∥μ∥2+E∥x−μ∥2)
Appendix
Table 14: Notation. All effective ranks use Eq. 5 on mean-centred matrices. The distinction between rcand and rquery is central: the former is what standard practice measures, the latter is where the failure lives.
Node type
count
Edge type
count
census-determined?
paper
57,903
(paper, has_claim, claim)
251,938
yes ( =∣ claim ∣ )
claim
251,938
(paper, has_method, method)
57,903
yes ( =∣ paper ∣ )
method
57,903
(paper, has_result, result)
57,903
yes ( =∣ paper ∣ )
result
57,903
(method, produces, result)
57,903
yes ( =∣ paper ∣ )
evidence
373,438
(result, grounds, claim)
251,938
yes ( =∣ claim ∣ )
implication
251,938
(claim, supported_by, evidence)
251,922
no (data-derived)
Appendix
Table 15: Heterogeneous graph statistics ( 57,903 maskable papers). The right-hand column is the reducibility audit of Sec. 9 : a relation whose cardinality equals an endpoint type’s node count is a deterministic function of the census and carries zero information.
Aspect
members/patch (mean)
max
patches with ≥2
mean in-degree
role
claim
4.35
10
99.5%
4.48
maskable, multi-member
method
1.00
1
0.0%
2.00
maskable, singleton
result
1.00
1
0.0%
6.35
maskable, singleton
Appendix
Table 16: Per-aspect membership and untrained in-degree. The singleton rows are what make the pooling control decisive.
Estimator
Assertion
Expected
AUC
perfect / inverted / constant / random
1.0 / 0.0 / 0.500 / ≈0.5
AUC ties †
constant scorer, ties averaged
exactly 0.500
balanced accuracy
always-majority on 95:5
0.500
Bmax †
matches the training code’s printed ceilings
10.108 , 14.379
retrieval
perfect / random bits
Bmax / ≈0
linear probe
separable / random labels
>0.90 / ≈0.5
Appendix
Table 17: The 20 assertions that must pass before any measurement is taken. The harness refuses to proceed on failure. Items marked † were added after an earlier version of the pipeline produced a confidently wrong number that the assertion would have caught; we list them in that spirit rather than as boilerplate.
Name
Meaning
Value
collapse_bits
below this many bits, a system is “collapsed”
1.0
probe_encodes_bits
above this, the context linearly encodes identity
4.0
control_capable_bits
above this, a control demonstrates capability
1.0
paired_alpha
level for paired bootstrap intervals
0.05
degenerate_bits_eps
below this gap, a control is degenerate with the model
10−3
sim_match_bits
tolerance for “simulation reproduces observation”
1.0
Appendix
Table 18: Decision thresholds, fixed and written to disk before any result was computed and not revised afterwards. Each converts a measurement into a verdict; publishing them is what makes the verdicts auditable. The last four are the target-side gates introduced for Sec. 9 .
Frame
MRR
note
raw
1.7×10−4
—
centre
2.1×10−4
shared mean removed
all-but-the-top- 1
2.6×10−4
best
all-but-the-top- 2
2.1×10−4
—
ZCA (fitted on candidates)
2.2×10−4
full whitening
candidate bank
DC ratio 37.6
rcand=18.1
Appendix
Table 19: Post-hoc retrieval-frame sweep (three seeds, block A). All frames are fitted on the candidate bank and applied to both sides. The best frame buys 0.4 bits against a 14.4 bits deficit, as Prop. 3 predicts. This is a different experiment from the trained target-frame effect of App. A14 and the two must not be conflated: this sweep re-metrises an already-collapsed query bank, whereas that one changes what the objective asks for.
Frame
shared
B
% of Bmax
A1 probe
raw
0 (baseline)
14.289
99.4%
0.964
center
0
14.359
99.9%
0.862
raw
1
11.808
82.1%
0.985
center
1
14.379
100.0%
0.963
target-frame main effect
+0.071
79% of the 0.090 available
shared-basis main effect
−2.481
Appendix
Table 20: The 2×2 over target frame and shared basis at matched budget ( 3 k steps, one seed, block C, ceiling 14.379 ; center removes the per-aspect target mean, shared ties the input projection across node types). Read the factorial, not the best cell. The baseline cell already reaches 99.4% of ceiling, so only 0.090 bits are available to any factor here; this is the reducibility of Prop. 5 showing up as a compressed dynamic range.
Property
Value
Note
pre-registered void line
0.70
App. A10
observed range across cells
0.711−0.985
Table 6
Appendix
Table 21: The A1 probe: construction, references and floors. The void line 0.70 is pre-registered (App. A10 ): a reading below it is treated as carrying no signal, and no cell in Table 6 falls below it.
Quantity
Value
Note
claim nodes
251,938
supported_by edges
251,922
≈1 per claim
challenged_by edges
121,516
48.2% of claims
evidence nodes
373,438
=251,922+121,516 exactly
implies edges
251,938
1 per claim (census-determined)
papers with ≥1 challenge
35,650
61.6% of corpus
Appendix
Table 22: Census of the data-derived relations (block C). Every evidence node is a leaf— 373,438=251,922+121,516 exactly—because the source fields are plain strings, so each claim yields one supporting and at most one contradicting evidence node. This is the structural fact behind the +0.1465 -AUC edge-type leak.
Aspect
m
rnode
rpool
rquery
MRR
MRR (centred)
margin z
claim
4.35
5.40
4.91
1.87
1.5×10−4
2.2×10−4
−0.006
method
1.00
47.42
47.31
1.97
2.1×10−4
1.5×10−4
−0.001
result
1.00
2.04
2.05
1.62
2.0×10−4
2.0×10−4
+0.033
Chance
1.99×10−4
1.99×10−4
0
Appendix
Table 23: Per-aspect breakdown (block A, five seeds). method and result are exact singletons, so mean pooling is the identity map: rnode≈rpool to two decimals. z is the gold item’s standardised similarity margin; z≈0 means the gold candidate is indistinguishable from the pool mean.
Figure 4: The control that exonerates pooling and localises the failure to the query side. (a) For method , m=1.00 , so mean pooling is provably the identity map: node rank 47.4 carries through to pooled rank 47.3 . The model’s predictions for those patches nevertheless occupy effective rank 1.97 (black diamonds), at or below the 3 -category bound of Prop. 1 . (b) A 23× range in pooled rank produces no movement in bits recovered; dotted line is chance, dashed line the 14.379 -bit ceiling. Five seeds.
Quantity
Value ( /128 )
Node-latent effective rank rnode
18.3±0.9
healthy
Pooled-latent effective rank rpool
1.97±0.04
low, but see Table 23
Appendix
Table 24: Isolated pre-target rank measurement. A mean-pool JEPA with a Euclidean-cosine target, no hyperbolic map and no anchors. Mean ± std over five seeds. The per-aspect breakdown above shows this aggregate conceals a 23× spread—which is why the aggregate, alone, misled us.
Features
Aspect
ctx MRR
no-summary
bm25
bm25-no-ov
whitened
claim
0.973
0.953
0.979
0.732
method
0.908
0.834
0.974
0.802
result
0.938
0.921
0.989
0.854
raw
claim
0.943
0.916
—
—
method
0.878
0.796
—
—
result
0.925
0.916
—
—
Appendix
Table 25: Oracle retrieval and leakage controls , per aspect, block A. bm25-no-ov is a lower bound on the non-lexical signal; bm25 uses no learned representation. no-summary removes the paper title/abstract node from the context. A cheat query equal to the target’s own embedding validates the metric.
Figure 5: Four training-free or positive-control retrievers, all near ceiling; the baseline trained model at chance (dotted). bm25 is the strongest evidence because it uses no learned representation whatsoever, and bm25-no-ov still recovers +14.250 bits— 99.1% of the 14.385 -bit ceiling—after deleting every shared 5 -gram.
frozen text features
hetero node features
reference predictor
+14.220 bits ( p1 )
not yet reported
full pipeline
not yet reported
0.00 bits (Table 1 )
Appendix
Table 26: Factorial design. The two diagonal cells are the systems reported in the main text; the off-diagonal cells isolate each factor and are not yet reported. We list them explicitly rather than omitting them, so that the limits of the attribution are visible: on the evidence in this paper, p1 bounds the harness and does not separate feature space from trainer. Both missing cells are 3 k-step runs on the existing cache.
ρ
0.0040
0.5
0.9
0.99
0.9961
0.999
0.9999
MRR, ρ only
1.000
1.000
0.8928
0.1068
0.0204
0.0043
0.0014
B , ρ only
+12.845
+12.845
+12.200
+3.833
+1.911
+0.843
+0.266
MRR, matched κ^,ε^
1.000
—
—
—
0.0171
—
—
B , matched
+12.845
—
—
—
+1.80
—
—
bits lost, matched
0.000
—
—
—
11.045
—
—
Leave-one-out at the measured operating point
Appendix
Table 27: Phase analysis, full sweep (bank size 20,000 , so Bmax=12.845 by Eq. 4 ). Row 1 varies ρ with κ=ε=0 ; row 2 uses the measured κ^=0.942,ε^=1.515 . The leave-one-out block shows that neither nuisance parameter is load-bearing.
Figure 6: The objective optimises the wrong variance component. Left: the frozen inputs, 86.05% of variance between papers. Right: the trained latents, 0.39% . Whitening the inputs raises the trained instance share to 9.86% and bits recovered still do not move—the invariance Prop. 1 predicts; changing the objective does (Table 6 ).
Pooling
Loss
rpool
probe
MRR
B
mean
1−cos (baseline)
1.97
0.871
1.9×10−4
0.00
mean
infonce
1.96
0.867
2.1×10−4
0.00
sum
1−cos
1.25
0.963
1.8×10−4
0.00
deepsets
1−cos
1.70
0.604
1.9×10−4
0.00
deepsets
infonce
1.81
0.742
1.7×10−4
0.00
attn
infonce
2.03
0.964
2.3×10−4
0.00
Appendix
Table 28: Seven interventions, one flat line (block A, five seeds, Protocol R). rpool spans 1.25 – 2.03 and the probe spans 0.604 – 0.964 ; bits recovered stay at 0 in every cell, against a ceiling of 14.379 . What this grid does not vary is the target frame and the learning-rate schedule, both of which App. A14 shows to matter; we therefore present it as a negative result about the aggregator and the in-batch-negative form of the loss, not about the pipeline.
Figure 7: Seven interventions, one flat line. Raw and centred cosine, mean ± std over five seeds. Dotted line is chance ( B=0 ), dashed line the 14.379 -bit ceiling.
Objective
Target construction
Probe acc
rpool/128
Rank verdict
hyperbolic, 2-D
mean (own only)
0.840
1.9
collapsed
rel-hetero + white
0.822
3.1
collapsed
rel-hetero (raw)
0.940
1.8
collapsed
hyperbolic + vic
mean (own only)
0.859
2.0
collapsed
rel-hetero + white
0.812
13.9
rank-recovered
rel-hetero (raw)
0.954
2.2
collapsed
Appendix
Table 29: Twenty objective × target-construction cells; the dissociation holds across all of them. Probe accuracy spans 0.755 – 0.960 and pooled effective rank 1.8 – 13.9 —a 7.7× range including two cells that clear the conventional rpool>10 threshold—with no accompanying change in retrieval. Mean over five seeds.
Objective
Target
Probe acc
rpool/128
rtgt
hyperbolic, 2-D
mean (2-D)
0.840
1.9
2.0 (ceiling)
k=4 ( →R8 )
0.869
1.9
1.6
k=16 ( →R32 )
0.869
1.9
1.9
k=64 ( →R128 )
0.867
1.9
1.9
hyperbolic + vic
mean (2-D)
0.859
2.0
2.0 (ceiling)
k=4
0.859
2.0
1.7
Appendix
Table 30: Raising the target’s algebraic rank ceiling from 2 to 2k does not raise the measured target rank. Each patch angle is replaced by k angles against QR-orthonormalised anchors. The ceiling rises to 128 at k=64 and the measured target effective rank rtgt does not move.
Probe
Detail
Value
aspect classification, function words only
fixed stopword vocabulary
0.937
aspect classification, full TF-IDF
50 k features
0.986
chance
three aspects
0.333
templating index
(acc−chance)/(1−chance)
0.906
top 4 -gram coverage, claim
“this suggests that the”
31.8%
top 4 -gram coverage, method
“the study employed a”
39.0%
Appendix
Table 31: Templating audit on the 58,145 set; text probes on an 8,000 -document subsample, variance probes on all records. The function-word classifier uses a fixed stopword vocabulary and cannot access content. The final block is the placeholder-text audit of Sec. 9 , on the block-C relations.
Dataset
ours
reported
verdict
MUTAG
0.686
0.874
not reproduced
PROTEINS
0.739
0.750
within tolerance
Appendix
Table 32: Our reference re-implementation on the original method’s graph-classification benchmarks. We do not clear MUTAG and therefore do not claim implementation faithfulness.
claim
method
result
paper
whitened
320.8
309.2
313.1
313.1
Appendix
Table 33: Effective rank of the frozen input features (of 384 ) per node type after PCA/ZCA whitening, applied per node type before the encoder. The per-node-type raw input ranks were not written to the released logs for this run and we therefore do not tabulate them; raw input anisotropy is instead characterised by the depth- 0 DC ratios of App. A29 ( 3.1 – 3.6 ), and the aggregate raw-to-whitened change is the 310.9 -of- 384 figure quoted for rung 4 of Table 1 . The whitened values below are the ones the ladder’s rank-restoration claim rests on.
Figure 8: Trained patches form one point-mass per aspect. First two principal components. Trained representations (left, centre) occupy two or three tight clusters corresponding to aspect type; the frozen features (right) form a diffuse cloud in which individual papers are separable. The representation encodes which aspect , not which paper —the visual form of Table 3 and of the erank≤∣A∣ bound of Prop. 1 .
Figure 9: Depth is not the binding factor. (a) Bits recovered across six encoder configurations from a depth- 0 linear map to a depth- 3 GNN; all at chance, the 14.379 -bit ceiling dashed. (b) Message passing compresses node rank monotonically ( 54.9→18.0 ) and the pooled rank is flat regardless.
Figure 10: Nothing is learned away. (a) Training loss converges within ∼15 epochs, on a twin axis because the cosine and InfoNCE losses differ by an order of magnitude—and note that this is exactly the comparison Sec. 9 warns against making on magnitude alone, since a regression loss near zero is collapse while an InfoNCE loss near zero is discrimination. (b) Pooled effective rank is already at its final value at epoch 0 and stays flat: the baseline pathology is present at initialisation rather than induced by optimisation, which is why Sec. 7.1 measures the variance allocation per checkpoint rather than asserting a re-allocation. Contrast the repaired configuration, whose bits rise from −0.07 at step 1 to +14.24 by step 500 (App. A14 ); the difference between the two trajectories is the objective , as the single-variable regression control establishes.
Figure 11: Bits recovered against pool difficulty for the three ceilings and the lexical no-overlap control (Table 2 ). All four series are ceilings or controls— bm25 , bm25-no-ov , oracle and the p1 positive control—and all four track the N1log2N! envelope with a near-constant deficit across a 5,800× change in pool size. The baseline Graph-JEPA is the single point at 0 bits at the right-hand end. This figure replaces every ratio-to-chance statement in earlier drafts.
Figure 12: Shared-mean dominance by pipeline stage. DC ratio ∥μ∥/E∥x−μ∥ on a log axis. The frozen features sit near 10−2 ; the trained query bank sits at 162.2 —a factor of ∼104 .
Figure 13: A constant query cannot be rescued by any frame applied after training. Five retrieval frames fitted on the candidate bank; the best buys 0.4 bits against a 14.4 bits deficit to the ceiling (dashed). This is a quantitative confirmation of Prop. 3 rather than a failed ablation: the way out is to change what the objective asks for, and the single-variable demonstration of that is the loss ablation of Sec. 9 ( 14.359→0.307 bits), not any transformation of the retrieval space.
Table 34: Measured compute budget. The Protocol R diagnosis costs 0.77 GPU-hours; the additional diagnostic harness of Secs. 6 – 7 costs 4.7 minutes on the same node. The low cost is deliberate: every check recommended in Sec. 10 is cheap enough to run before committing to a training budget—and the two checks that changed this paper’s conclusions, the reducibility audit and the duplicate census, are the two cheapest lines in the table.
Self-supervised learning on graphs is largely shaped by contrastive methods that depend on carefully designed augmentations, and by generative methods that reconstruct node attributes in the input space. Both paradigms can entangle representations with low-level input statistics rather than with relational structure. Joint-embedding predictive architectures (JEPA) instead learn by predicting latent targets rather than reconstructing inputs. Recent work has explored this idea for graph-level representation learning, but how to design JEPA-style objectives for node-level tasks, and which structural signals the predictor should condition on, remains less clear. We present NodeJEPA, a joint-embedding predictive architecture for node-level graph self-supervised learning. NodeJEPA masks structure-aware k-hop ego-subgraphs and trains a context encoder to predict the latent representations of the masked nodes. These targets come from an EMA-updated target encoder with stop-gradient. A structure-conditioned predictor integrates spectral and centrality descriptors through cross-attention. Variance, covariance, and Laplacian spectral regularizers help stabilize the embedding geometry, and an optional curriculum gradually increases masking difficulty during training. Because prediction occurs in latent space, NodeJEPA does not rely on input reconstruction or hand-crafted graph augmentations. We evaluate NodeJEPA on standard node classification benchmarks under linear probing and fine-tuning protocols, and conduct ablations on masking, prediction, and regularization design choices. Our study offers a practical recipe for node-level JEPA-style latent prediction on graphs, and clarifies when structural conditioning helps representation learning. Code, configurations, and evaluation scripts are publicly available at https://github.com/OliverZ-dot/Node-Jepa.
Large language models fail on multi-step compositional reasoning, but measuring that failure is hard, because new models are trained on the benchmarks used to evaluate them. A fixed test set becomes a memorisation check soon after release. Constructive benchmarks avoid this by generating instances on demand. We introduce ClosureBench, a constructive benchmark for graph-relational logical reasoning. Each task is built from explicit primitives (reachability, degree, set operations, connectivity, aggregation), and its reference answer is computed by executing code that implements that logic exactly. Ground truth is therefore verified, and the supply of fresh instances is unlimited. The benchmark spans 26 task categories at three compositional levels, with three independent difficulty axes: graph size, edge density, and query depth. We evaluate models from 1.5B open weights to frontier systems (o3, GPT-4.1, Gemini 2.5, Claude Sonnet 4). Accuracy falls as graph size and query depth increase, and the two axes interact. The difficulty does not lie in the surface form, since it persists when the graph is given as a JSON edge list or an adjacency matrix rather than prose, nor in the reasoning rule, which models state correctly. It lies in carrying that rule out over the graph across many steps. A 4B model fine-tuned to emit verified programs instead of answers stays nearly flat across compositional levels, while every frontier model degrades. o3 falls from 96% on atomic queries to 82% on the most compositional; the 4B model holds at 93% at a fraction of the token cost. The program offloads multi-step execution to a runtime, and the model's remaining errors are almost entirely misread edges. Constructive generation also supports a direct memorisation check, comparing accuracy on seen and fresh instances.
Scientific Reasoning Graph Extraction (SRGE) aims to recover explicit links among observations, evidence, intermediate claims, and paper-level conclusions. LLMs can produce graph-like scientific explanations, but their outputs often mix malformed syntax, drifting edge labels, incorrectly oriented roots, and weak source anchors. We propose PEARL (Peircean Extraction via Abstraction and Repair Layer), a training-free framework that turns noisy LLM graph responses into auditable reasoning graphs and repairs them toward strict semantic validity. PEARL first materializes explicit graph content under a closed Peircean schema, then uses matched evidence-grounded judge feedback to repair rejected edge types, local inference steps, and terminal roots while preserving an audit trail. On five 70-paper model archives from ARCHE, a benchmark for latent reasoning-chain extraction, PEARL raises strict gate passes from 0/350 for the LLM baseline to 300/350, with average REA improving from 0.339 to 0.906. The graphs provide a reliability layer for research-agent and AI scientist workflows that need inspectable reasoning traces rather than unconstrained graph regeneration. Code and audit artifacts are available at https://github.com/BohanSu/auditable-repair-reasoning-graphs/tree/300-350_workshop .
Bohan Su, Pengze Li, Yuchen Lu +1
School of Computer Science, Wuhan University · Artificial Intelligence Innovation and Incubation, Fudan University · Department of Computer Science, Faculty of Science, University of Bath +1