Multimodal graph learning has recently emerged as an effective paradigm for in corporating inter-entity relationships into multimodal representations. Existing studies have made substantial progress on how to construct and optimize graphs, but rarely consider a more fundamental question: whether additional relational structures should be introduced for a given dataset and task. Through empirical studies across diverse datasets, tasks, and graph constructors, we reveal that graphification is not consistently beneficial: introducing relational structures can provide substantial improvements in some cases, while offering limited or even negative gains. This observation motivates a new perspective that graph construction should be treated as a selective decision based on its expected utility rather than a default preprocessing step. To address this issue, we propose MAG-SCOUT, a pre-construction graph assessment framework that estimates whether introducing graph structures is beneficial before generating the complete topology. MAG-SCOUT collects limited relational evidence, analyzes its potential taskspecific contribution, and estimates the expected utility of graphification together with construction cost to make a build-or-skip decision. Extensive experiments across six multimodal datasets, three downstream tasks, and diverse graph constructors demonstrate that MAG-SCOUT effectively identifies when graph structures should be introduced, saving 33.1% of task-macro graph work while retaining 96.7% of held-out positive-gain mass under the pre-registered floor.
Figures & tables
Constructor
Node classification (Acc)
Link prediction (AUC)
Cross-modal retrieval (R@5)
Toys
Grocery
Bili Music
DY
QB
Bili Cartoon
kNN-GCN
+0.58 ±0.31
+2.25 ±0.30
-4.17 ±1.34
-3.77 ±0.61
-3.65 ±2.03
-0.08 ±2.54
MM-kNN-GCN
+0.92 ±0.36
+1.93 ±0.08
-3.89 ±1.27
-2.39 ±0.49
+0.33 ±0.82
-0.34 ±1.34
AutoG
+4.26 ±0.19
+2.92 ±0.16
-0.87 ±0.49
-3.80 ±0.62
-2.41 ±1.14
+1.56 ±0.96
AutoGraph
+7.27 ±0.60
+6.79 ±0.60
+2.02 ±0.49
-2.13 ±1.41
-3.26 ±0.70
-0.34 ±1.37
auGraph
+5.11 ±0.29
+4.97 ±0.27
+1.23 ±0.92
-2.81 ±1.08
-4.31 ±1.83
-0.30 ±1.26
Table 1: GraphGain relative to RawOnly across six multimodal benchmarks, in percentage points ( Δ≡0 ). Cells report five-seed means with standard deviations. All nine constructors are included. The Average row is their unweighted mean on each dataset.
Figure 1: Overview of MAG-Scout : (1) Relational encoding on P yields compact sketch SB ; (2) Tri-bottleneck reasoning ( eN,eC,eU ) estimates value μV and scale σV ; (3) Cost-aware gating uses calibrated scale σ~V to render Build/Skip decisions.
Figure 2: Macro prediction quality across five methods and three task families on the 13 parent sources. Panels report Spearman correlation, Kendall correlation, and gain MAE.
Predictor
Spearman rank correlation ( ρ↑ )
Kendall rank correlation ( τ↑ )
Gain error ( MAE↓ )
NC
LP
CMR
NC
LP
CMR
NC
LP
CMR
MAG-Scout
0.417 ±0.05
0.383 ±0.06
0.276 ±0.06
0.362 ±0.03
0.331 ±0.03
0.253 ±0.08
1.63 ±0.17
6.83 ±0.45
3.97 ±0.29
NetInfoF
0.358 ±0.11
0.429 ±0.08
0.099 ±0.13
0.318 ±0.07
0.295 ±0.06
0.074 ±0.06
2.14 ±0.24
8.48 ±1.53
5.22 ±0.53
WDGH
0.336 ±0.12
0.414 ±0.07
0.079 ±0.12
0.294 ±0.11
0.282 ±0.06
0.068 ±0.08
2.39 ±0.22
8.74 ±1.36
4.82 ±0.79
GLEMOS-S2
0.182 ±0.08
0.342 ±0.11
0.059 ±0.08
0.155 ±0.08
0.279 ±0.08
0.046 ±0.06
2.89 ±0.28
7.94 ±0.93
5.70 ±0.72
MetaGL
0.167 ±0.09
0.298 ±0.10
0.037 ±0.12
0.132 ±0.11
0.246 ±0.10
0.027 ±0.09
3.45 ±0.59
7.54 ±1.18
4.76 ±0.67
Table 2: Pre-construction prediction quality across the 13 parent sources. Cells report task-family means with seed-level standard deviations; bold and underline indicate the best and second-best values.
Ablation Variant
Spearman ρ ( ↑ )
Kendall τ ( ↑ )
Gain error (MAE ↓ )
NC
LP
CMR
NC
LP
CMR
NC
LP
CMR
Full MAG-Scout (Reference)
0.418 ±0.058
0.379 ±0.047
0.276 ±0.071
0.361 ±0.034
0.324 ±0.041
0.238 ±0.052
1.716 ±0.112
6.748 ±0.418
3.964 ±0.346
Frozen Heuristic Sketch
0.396 ±0.041
0.351 ±0.053
0.241 ±0.036
0.342 ±0.039
0.297 ±0.046
0.209 ±0.033
1.893 ±0.168
7.164 ±0.514
4.218 ±0.431
w/o Necessity ( eN )
0.361 ±0.064
0.341 ±0.049
0.208 ±0.043
0.312 ±0.058
0.286 ±0.051
0.174 ±0.064
2.163 ±0.246
7.514 ±0.581
4.581 ±0.374
w/o Constructability ( eC )
0.347 ±0.057
0.328 ±0.038
0.239 ±0.082
0.301 ±0.043
0.274 ±0.067
0.206 ±0.072
2.087 ±0.138
7.628 ±0.894
4.443 ±0.476
w/o Utility ( eU )
0.339 ±0.046
0.286 ±0.054
0.214 ±0.051
0.287 ±0.031
0.241 ±0.063
0.183 ±0.038
2.458 ±0.184
8.247 ±0.512
4.916 ±0.467
Table 3: Matched component-ablation results on the separate rebuilt source bank across node classification, link prediction, and cross-modal retrieval. Cells report means with seed-level standard deviations; bold marks the best value in each column.
Figure 4: Build/Skip comparison across five predictors: threshold trade-offs, retained-gain floors, and warm decision latency.
Figure 5: One-factor retained mass at a zero threshold, the threshold trade-off, and gain error under input perturbations.
Dimension
Pts
t=0 Ref.
t=0 Best (Spread)
Perturbation
Δ Ret.
Δ Build
Flips
Learning Rate
3
81.9
83.6 (1.7)
Rewiring
−0.4
−7.1
2/13
BCE Loss Weight
3
96.2
96.5 (0.3)
Relation Collapse
−0.8
−7.1
2/13
Relation Budget
3
87.8
88.2 (0.4)
Single-Modal Dominant
−1.6
−14.3
3/13
Utility Head Width
3
93.0
93.4 (0.4)
Relation-Bank Partition
−0.1
−0.2
0/13
Table 4: Zero-threshold sensitivity (left) and frozen-policy evidence corruption (right) on 13 parent sources. Each factor has its own reference. Best (Spread) is the grid maximum and its difference from that reference.
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
Symbol
Meaning
D=(V,{X(m)}m∈M)
multimodal dataset: entity set V (cardinality N=∣V∣ ) with modality tensors X(m)
M
set of observed modalities (text, visual, and auxiliary attributes)
T , C
downstream task and candidate graph constructor
C(D)=(V,EC,AC)
graph induced by constructor C
H={hi}i=1N∈RN×d
frozen multimodal entity representations ( Emm )
hi(m)
modality- m representation of entity i
Appendix
Table 5: Notation used throughout the methodology. Dimensions are for a single source; the encoder width is d and the reduced projection width is d′≪d .
Task
Nominal
Raw coverage
Calibrated coverage
Raw width
Calibrated width
Raw / calibrated NLL
NC
80%
72.5
77.4
4.69
3.66
1.48 / 1.22
NC
90%
82.9
87.6
6.02
4.70
1.48 / 1.22
NC
95%
88.1
92.7
7.17
5.60
1.48 / 1.22
LP
80%
70.8
76.8
6.84
5.33
1.74 / 1.42
LP
90%
81.2
87.0
8.78
6.84
1.74 / 1.42
LP
95%
86.4
92.1
10.46
8.15
1.74 / 1.42
Appendix
Table 6: Source-held-out uncertainty diagnostics before and after scale calibration. Coverage is reported at each nominal interval level; width is in GraphGain percentage points.
zij=ϕθ([hi∥hj∥hi⊙hj∥∣hi−hj∣∥t∥c]).
Appendix
Table 11
Benchmark
Downstream Task
Entities ( ∣V∣ )
Source Edges
Modalities
Dims (T/V)
Classes / Targets
Split (Train/Val/Test)
Toys
Node Classification
20,695
126,886
Text, Visual
768 / 768
18 categories
60% / 20% / 20%
Grocery
Node Classification
17,074
171,340
Text, Visual
768 / 768
20 categories
60% / 20% / 20%
Bili Music
Link Prediction
6,038
21,592
Text, Visual
768 / 768
Binary interaction
70% / 10% / 20%
DY
Link Prediction
8,299
35,627
Text, Visual
768 / 768
Binary interaction
70% / 10% / 20%
QB
Cross-modal Retrieval
6,121
24,145
Text, Visual
768 / 768
Query-Item Pairs
60% / 20% / 20%
Bili Cartoon
Cross-modal Retrieval
4,724
18,660
Text, Visual
768 / 768
Query-Video Pairs
60% / 20% / 20%
Appendix
Table 7: Source benchmark statistics for the six datasets. Source edges are published graph counts. Feature dimensions correspond to frozen text and visual encoders; split ratios specify the evaluation protocol, including a held-out-edge split for link prediction.
Ablation Variant
Δ Spearman ρ
Δ Kendall τ
Δ MAE
NC
LP
CMR
NC
LP
CMR
NC
LP
CMR
Frozen Heuristic Sketch
−0.022
−0.028
−0.035
−0.019
−0.027
−0.029
+0.177
+0.416
+0.254
w/o Necessity ( eN )
−0.057
−0.038
−0.068
−0.049
−0.038
−0.064
+0.447
+0.766
+0.617
w/o Constructability ( eC )
−0.071
−0.051
−0.037
−0.060
−0.050
−0.032
+0.371
+0.880
+0.479
w/o Utility ( eU )
−0.079
−0.093
−0.062
−0.074
−0.083
−0.055
+0.742
+1.499
+0.952
Uniform Bottleneck Gates
−0.137
−0.105
−0.085
−0.115
−0.095
−0.071
+0.625
+1.158
+0.765
Appendix
Table 8: Component ablations on the rebuilt 11-source bank, reported as differences from Full MAG-Scout in Table 6.3 . Rank correlations are subtracted from Full. MAE differences are positive when absolute error increases. The bank has 5 node-classification, 4 link-prediction, and 2 cross-modal sources, with three model seeds.
Method
Held-out Retained Gain Mass (%)
Avoided Graph Work (%)
90%
92.5%
95%
97.5%
99%
90%
92.5%
95%
97.5%
99%
MAG-Scout
96.7
96.7
96.7
96.8 ∗
96.8 ∗
24.2
24.2
23.6
19.6
18.4
NetInfoF
96.3
96.4
96.4
96.4 ∗
97.6 ∗
24.3
23.5
23.2
22.6
21.8
WDGH
85.4 ∗
90.5 ∗
90.5 ∗
90.5 ∗
90.5 ∗
25.0
23.8
23.5
22.3
22.3
GLEMOS-S2
60.0 ∗
60.2 ∗
60.5 ∗
60.9 ∗
64.2 ∗
34.8
32.9
30.3
28.6
24.1
MetaGL
80.2 ∗
80.2 ∗
80.2 ∗
80.4 ∗
83.5 ∗
32.6
32.6
32.6
29.7
25.9
Appendix
Table 9: Build/Skip policies at five retention floors on 13 parent sources. An asterisk ( ∗ ) marks a held-out retention below the floor named in that column.
Configuration
Grid Points
Retained (%)
Δ ref (percentage points)
Selected setting in Figure 6.5 (a)
4
81.9 / 96.2 / 87.8 / 93.0
0
Learning Rate ( 0.001→0.004 )
3
83.6
+1.7
BCE Loss Weight ( 0.0→1.0 )
3
96.5
+0.3
Relation Budget ( 0.50→0.75 )
3
88.2
+0.4
Utility Head Width ( 16→48 )
3
93.4
+0.4
Retained-fraction × loss-weight interaction grid (all four cells)
Appendix
Table 10: One-factor sensitivity at a fixed zero threshold, followed by the budget × loss-weight grid. Retained mass is task-macro positive-gain mass. One-factor differences use that factor’s reference: 81.9, 96.2, 87.8, and 93.0. Interaction differences use the 90.5 grid reference.
Perturbation Family
Scope
Δ Ret.
Δ Build
Flips
Rewiring
Macro (13)
−0.4
−7.1
2/13
Node classification (5)
−0.7
−13.4
1/5
Link prediction (5)
−0.3
−4.7
1/5
Cross-modal retrieval (4)
−0.2
−2.2
0/4
Relation Collapse
Macro (13)
−0.8
−7.1
2/13
Node classification (5)
−1.4
−12.1
1/5
Appendix
Table 11: Frozen-threshold evidence corruption on 13 parent sources. The predictor and threshold are frozen before perturbation. Δ Ret. is the task-macro change in retained positive-gain mass; Δ Build is the build-rate change in percentage points. Macro flips count parent sources. Task rows count evaluations: the books parent contributes one node-classification evaluation and one link-prediction evaluation.