aiqbench analysis
This study resolves a key trainability bottleneck by distinguishing between nominal layer counts and effective information paths in CNNs, demonstrating that residual and multi-branch architectures maintain scalability where plain stacks saturate. By formalizing the "Effective Depth Paradox," the research provides actionable metrics for optimizing network topology without relying solely on depth scaling.
The Effective Depth Paradox: Topology and Trainability in Deep CNNs
arXiv:2602.13298v4 Announce Type: replace-cross Abstract: This paper presents a controlled comparative study of convolutional neural network (CNN) topology and image classification performance across the architectural families VGG, ResNet, and GoogLeNet, evaluated on CIFAR-10 under a unified training protocol. We formalize the distinction between nominal depth ($D_{\mathrm{nom}}$), the physical count of weight-bearing layers, and effective depth ($D_{\mathrm{eff}}$), an operational metric quantifying the expected length of forward information paths, extending the path-ensemble interpretation of residual networks introduced by Veit et al. (2016) into closed-form, pre-training proxies spanning sequential, residual, and multi-branch topologies. We validate this proxy against a gradient-weighted variant computed from observed backpropagation signal. Across eight representative models (VGG-11/13/16/19, ResNet-18/34/50, GoogLeNet), plain VGG-style stacks show early accuracy saturation as $D_{\mathrm{eff}}$ increases, whereas ResNet and GoogLeNet continue to benefit from added depth by keeping $D_{\mathrm{eff}}$ low relative to $D_{\mathrm{nom}}$ - a pattern we term the "Effective Depth Paradox". A pooled correlation analysis shows both $D_{\mathrm{nom}}$ and $D_{\mathrm{eff}}$ are strongly, significantly associated with accuracy (r = 0.94 and r = 0.93; both p < 0.01); given the small family-clustered sample, this alone cannot cleanly separate the two metrics, so we treat gradient-norm evidence as complementary mechanistic support rather than decisive statistical proof. We conclude that architectural topology, not layer count alone, governs trainability and scaling efficiency in deep CNNs. All claims are scoped to CIFAR-10-scale training of the three families studied; we do not claim validation at ImageNet scale or generalization to modern architectures such as EfficientNet, ConvNeXt, or Vision Transformers, which we identify as necessary future work.
Abstract:This paper presents a controlled comparative study of convolutional neural network (CNN) topology and image classification performance across the architectural families VGG, ResNet, and GoogLeNet, evaluated on CIFAR-10 under a unified training protocol. We formalize the distinction between nominal depth ($D_{\mathrm{nom}}$), the physical count of weight-bearing layers, and effective depth ($D_{\mathrm{eff}}$), an operational metric quantifying the expected length of forward information paths, extending the path-ensemble interpretation of residual networks introduced by Veit et al. (2016) into closed-form, pre-training proxies spanning sequential, residual, and multi-branch topologies. We validate this proxy against a gradient-weighted variant computed from observed backpropagation signal. Across eight representative models (VGG-11/13/16/19, ResNet-18/34/50, GoogLeNet), plain VGG-style stacks show early accuracy saturation as $D_{\mathrm{eff}}$ increases, whereas ResNet and GoogLeNet continue to benefit from added depth by keeping $D_{\mathrm{eff}}$ low relative to $D_{\mathrm{nom}}$ - a pattern we term the "Effective Depth Paradox". A pooled correlation analysis shows both $D_{\mathrm{nom}}$ and $D_{\mathrm{eff}}$ are strongly, significantly associated with accuracy (r = 0.94 and r = 0.93; both p < 0.01); given the small family-clustered sample, this alone cannot cleanly separate the two metrics, so we treat gradient-norm evidence as complementary mechanistic support rather than decisive statistical proof. We conclude that architectural topology, not layer count alone, governs trainability and scaling efficiency in deep CNNs. All claims are scoped to CIFAR-10-scale training of the three families studied; we do not claim validation at ImageNet scale or generalization to modern architectures such as EfficientNet, ConvNeXt, or Vision Transformers, which we identify as necessary future work.
Computer Vision and Pattern Recognition (cs.CV); Artificial Intelligence (cs.AI)
arXiv:2602.13298 [cs.CV]
(or arXiv:2602.13298v4 [cs.CV] for this version)
From: Manfred M. Fischer [view email] [v1] Mon, 9 Feb 2026 10:14:15 UTC (161 KB) [v2] Fri, 27 Mar 2026 09:02:37 UTC (152 KB) [v3] Fri, 8 May 2026 11:59:25 UTC (166 KB) [v4] Fri, 2 Oct 2026 09:51:14 UTC (491 KB)
Full text under the publisher's open licence · 309 words
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