We sincerely thank the reviewer for the efforts in reviewing our paper. Our responses according to the reviewer's questions are summarized as follows.
> W1: Is there a domain gap between personalized scenarios and general scenarios
Yes, absolutely. From a distributional perspective, the data distributions of the personalized domain (downstream target domain) and the general domain (pre-trained source domain) differ in two key aspects: the means of the distributions are distinct, and the variance in the personalized domain is typically smaller than that of the general domain. In our experiments, the domain gap can be clearly identified in the selected transfer tasks. For example, the CUB dataset includes fine-grained birds, and ArtBench-10 consists of images of artwork, while the pre-trained source domain, ImageNet, is collected from search engines and annotated into 1000 categories.
>W2: During the transfer learning process, does all the knowledge from the pre-trained model need to be effectively utilized?
No, not all knowledge from the pre-trained model is necessary for individual domains or tasks. Some knowledge may be domain-specific, while other knowledge can be beneficial across different domains, thereby improving performance for the target domain or task. In cases where the source and target domains are unrelated, brute-force transfer may be unsuccessful. Transfer learning focuses on transferring the beneficial parts of the knowledge from the pre-trained model across domains. Domain Guidance (DoG) provides novel techniques that leverage this pre-trained knowledge through unconditional guidance.
> W3: How can the impact of the knowledge in the pre-trained model be assessed in the target domain?
The impact of the pre-trained model in DoG consists of two parts: the first is the faster convergence and improved generation quality derived from the full fine-tuning process compared to training from scratch. The second part is brought by DoG itself, which can be assessed by the significant improvement over the standard Classifier-Free Guidance method. Generally, pre-trained models are well-trained on much larger datasets and tend to exhibit good generalization capabilities. However, these capabilities are often diminished in the fine-tuning process due to the catastrophic forgetting phenomenon. DoG utilizes this knowledge by directly incorporating outputs from the pre-trained model in the sampling process to enhance generation quality in the target domain.
> W4: For DF-20M (which has no overlap with ImageNet) and ArtBench-10 (whose feature distribution is completely distinct from ImageNet), why can guidance from the model pre-trained on ImageNet lead to better generation?
Although these domains are quite different in appearance, some beneficial common knowledge can still be leveraged. In the guidance process, the pre-trained models serve as the unconditional branch, from which the generation process is pushed away. When the domain gap is large, the fine-tuned model may struggle to fit the unconditional branch of the target domain due to limited optimization steps, during which we reduce the conditional signal. DoG provides a mechanism to leverage pre-trained knowledge to assist the generation process far from the pre-trained domain, a point supported by the improvements in our experimental results.
>W5: Is the distribution of the downstream domain a subset of the distribution of the pre-trained domain?
No, it is not nessissary that the domainstream domain is a subset of the distribution of the pre-trained domain.
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We hope that our additional clarifications and discussion address your questions and concerns. Please let us know if we miss some of your point or you have any further concerns!