自回归模型
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华人团队终结Token危机:扩散模型数据潜力超自回归三倍
量子位· 2025-08-13 09:13
Core Viewpoint - The article discusses the potential of diffusion language models (DLMs) in data learning, highlighting their ability to outperform autoregressive models in terms of data utilization and learning efficiency [1][4]. Group 1: Diffusion Language Models - Diffusion language models can achieve over three times the data potential compared to autoregressive models when token quantity is limited [1]. - A diffusion model with 1 billion parameters trained on 1 billion tokens for 480 cycles achieved 56% and 33% accuracy on HellaSwag and MMLU benchmarks, respectively, without any data filtering or tricks [5]. - The model's performance did not show saturation even under extreme repetition, indicating that it can extract more useful information from the data [4]. Group 2: Learning Mechanisms - The strong data learning capability of diffusion language models is attributed to two main factors: the diffusion objective and bidirectional attention mechanisms, allowing for comprehensive data utilization beyond causal relationships [8][9]. - Diffusion models invest more computational resources (FLOPs) during training and inference, enhancing model performance through iterative optimization [11]. - Unlike autoregressive models that prioritize computational efficiency, diffusion models focus on maximizing data potential, which leads to improved learning outcomes [14]. Group 3: Overfitting and Data Utilization - The research team observed that the number of training cycles before overfitting occurs is positively correlated with the amount of unique data and negatively correlated with model size [18]. - Even when overfitting occurs, the model's performance on downstream tasks may continue to improve, suggesting that absolute loss values do not necessarily translate to relative performance changes [19][21]. - The phenomenon of overconfidence in certain text segments after repeated exposure to limited training data may explain the observed performance trends [26][27]. Group 4: Future Research Directions - The research team plans to use larger models and more unique data in future studies to further validate their findings and hypotheses regarding diffusion language models [28].
扩散语言模型真的会比自回归好?理论分析结果可能恰恰相反
机器之心· 2025-06-10 08:41
Core Insights - The article discusses the potential of diffusion language models (DLMs) in text generation, comparing them to autoregressive models (ARMs) and highlighting the efficiency paradox observed in practical applications [1][3][7]. Group 1: Model Comparison - Autoregressive models generate text token-by-token, achieving high quality but limited by serial processing speed, especially for long sequences [3]. - Diffusion language models, particularly Masked Diffusion Models (MDMs), theoretically allow parallel sampling of multiple tokens, suggesting a potential efficiency improvement [3][4]. - However, practical experiments show that MDMs often require more sampling steps to match the accuracy of ARMs, leading to higher inference costs [3][4][12]. Group 2: Evaluation Metrics - The research emphasizes that the comparison between DLMs and ARMs heavily depends on the chosen evaluation metrics [10][15]. - Two key metrics are introduced: Token Error Rate (TER) for assessing token-level accuracy and Sequence Error Rate (SER) for evaluating overall sequence correctness [10][11]. - MDMs can demonstrate efficiency advantages when evaluated on TER, but they struggle with SER, particularly in tasks requiring logical consistency, such as mathematical reasoning [11][12][15]. Group 3: Practical Implications - The findings suggest that DLMs may be more suitable for tasks prioritizing text fluency and throughput, where some sequence-level imperfections are acceptable, such as creative writing [15]. - Conversely, for tasks demanding high sequence-level accuracy and logical correctness, ARMs remain the better choice due to the linear increase in sampling steps required by MDMs as sequence length grows [15][16]. - The research lays a theoretical foundation for understanding the comparative advantages and limitations of MDMs, indicating that the success of diffusion techniques in image generation does not directly translate to language generation [16].