How Good is ChatGPT in Giving Advice on Your Visualization Design?

Data visualization practitioners often lack formal training, resulting in a knowledge gap in visualization design best practices. Large-language models like ChatGPT, with their vast internet-scale training data, offer transformative potential in addressing this gap. To explore this potential, we adopted a mixed-method approach. Initially, we analyzed the VisGuide forum, a repository of data visualization questions, by comparing ChatGPT-generated responses to human replies. Subsequently, our user study delved into practitioners' reactions and attitudes toward ChatGPT as a visualization assistant. Participants, who brought their visualizations and questions, received feedback from both human experts and ChatGPT in a randomized order. They filled out experience surveys and shared deeper insights through post-interviews. The results highlight the unique advantages and disadvantages of ChatGPT, such as its ability to quickly provide a wide range of design options based on a broad knowledge base, while also revealing its limitations in terms of depth and critical thinking capabilities.