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.
Multimodal-attributed graphs (MAGs) are a fundamental data structure for multimodal graph learning (MGL), enabling both graph-centric and modality-centric tasks. However, our empirical analysis reveals inherent topology quality limitations in real-world MAGs, including noisy interactions, missing connections, and task-agnostic relational structures. A single graph derived from generic relationships is therefore unlikely to be universally optimal for diverse downstream tasks. To address this challenge, we propose Task-aware Modality and Topology co-Evolution (TMTE), a novel MGL framework that jointly and iteratively optimizes graph topology and multimodal representations toward the target task. TMTE is motivated by the bidirectional coupling between modality and topology: multimodal attributes induce relational structures, while graph topology shapes modality representations. Concretely, TMTE casts topology evolution as multi-perspective metric learning over modality embeddings with an anchor-based approximation, and formulates modality evolution as smoothness-regularized fusion with cross-modal alignment, yielding a closed-loop task-aware co-evolution process. Extensive experiments on 9 MAG datasets and 1 non-graph multimodal dataset across 6 graph-centric and modality-centric tasks show that TMTE consistently achieves state-of-the-art performance. Our code is available at https://anonymous.4open.science/r/TMTE-1873.
Yinlin Zhu, Xunkai Li, Di Wu +3
Sun Yat-sen University, Guangzhou, China · Beijing Institute of Technology, Beijing, China
Multimodal graph learning requires jointly training over graph structure and heterogeneous node attributes, yet existing methods largely decouple these processes: prior multimodal graph neural networks (GNNs) focus on aligning modalities in a shared embedding space while operating on fixed or weakly adapted graph structures, and graph structure learning approaches infer topology from unimodal node representations without accounting for multimodal interactions. This separation fundamentally limits the ability of GNNs to capture semantically meaningful relationships in multimodal settings, where observed edges are often noisy, incomplete, or misaligned with underlying semantics. We propose ReCoG (Reciprocal Co-Evolution for Multimodal Graph Learning), a new learning paradigm that tightly couples graph structure learning and multimodal representation learning through end-to-end reciprocal interaction. Concretely, ReCoG integrates (i) a multimodal graph refiner that infers and corrects edges using cross-modal semantic evidence, and (ii) a coupled cross-modal message passing mechanism that performs joint intra- and inter-modality propagation over the refined graph. This unified design yields greater expressiveness than decoupled or two-stage formulations and allows dynamic interaction between topology and representation learning. Across diverse benchmarks for node classification and link prediction, ReCoG consistently outperforms strong multimodal graph structure learning baselines, including graph foundation models. Our results demonstrate that reciprocal co-evolution of structure and semantics is important for effective multimodal graph learning, challenging the prevailing separation between topology and representation learning.
Rui Xue, Tianfu Wu
Department of Electrical and Computer Engineering (ECE) North Carolina State University, Raleigh, NC 27695, USA
Multimodal attributed graphs (MAGs) combine multimodal node attributes with structured relations. However, existing methods usually perform shared message passing on a single graph and implicitly assume that the same neighbors are equally useful for all modalities. In practice, neighbors that benefit one modality may interfere with another, blurring modality-specific signals under shared propagation. To address this issue, we propose RoleMAG, a multimodal graph framework that learns how different neighbors should participate in propagation. Concretely, RoleMAG distinguishes whether a neighbor should provide shared, complementary, or heterophilous signals, and routes them through separate propagation channels. This enables cross-modal completion from complementary neighbors while keeping heterophilous ones out of shared smoothing. Extensive experiments on three graph-centric MAG benchmarks show that RoleMAG achieves the best results on RedditS and Bili_Dance, while remaining competitive on Toys. Ablation, robustness, and efficiency analyses further support the effectiveness of the proposed role-aware propagation design. Our code is available at https://anonymous.4open.science/r/RoleMAG-7EE0/