On March 30, Han Shangyou, president of TikTok’s parent Douyin, announced the launch of the “Douyin Safety and Trust Center” website. The site publicly disclosed the principles behind Douyin’s recommendation algorithm and explained how it predicts user behavior.
Why it matters: Since gaining attention in 2016, Douyin’s unique content recommendation algorithm has been seen as a key factor in its success. However, it has also raised concerns about creating filter bubbles and biases. Over the past nine years, China’s online environment has undergone significant changes, and as one of the country’s most popular social media platforms, Douyin has played a central role in shaping this digital landscape. With the public disclosure of its algorithm, Douyin aims to address the issues it has helped create.
Details: Douyin introduced two models: the Wide&Deep model and the Two-Tower Retrieval Model.
- The Wide&Deep model, as its name suggests, combines a single-layer Wide component with a multi-layer Deep component. The Wide component focuses on strengthening the model’s “memorization” ability, which refers to its capacity to learn directly from the co-occurrence frequencies of items or features in historical data. In contrast, the Deep component enhances the model’s “generalization” ability, allowing it to identify correlations between features and uncover links between rare or even unseen features and the final label.
- Two-Tower Retrieval Model is used to recommend content to users by converting both user and content features into numbers, like “0” for a cat video and “1” for a dog video. These numbers are fed into two separate deep learning models – one for users and one for content – creating unique “digital fingerprints” for both. The model then compares the user’s fingerprint with those of all available videos, measuring how close they are. The closer the fingerprints, the more likely the video is to be recommended. This approach helps the system match users with videos they might like without needing to understand the actual content, just the numbers.
The website also outlined the review process for governance on the Douyin platform, detailing how it handles challenges related to rumors, online harassment, and other violations.
Context: The actions follow a three-month government campaign, launched in late November, aimed at addressing common algorithmic issues on online platforms, such as filter bubbles, where users are exposed only to content that aligns with their views, and discriminatory pricing practices targeting different demographics. The campaign was led by the Communist Party’s cyberspace affairs commission, the Ministry of Industry and Information Technology, and other relevant government agencies.In January, Douyin Group announced plans to introduce ten measures aimed at increasing transparency on the platform, including efforts to make its algorithms and governance processes more open. On Jan. 8, Li Liang, vice president of Douyin, rejected the idea that the company’s content recommendation algorithms contribute to the creation of filter bubbles. He noted that ByteDance’s algorithms have come under global scrutiny, with specific concerns about filter bubbles and restricted content exposure.
