Recommendations To YouTube 1 Disclose more information about how the platform works For all of the controversy in recent years about the detrimental side effects of widespread use of social media, the public, researchers, and policymakers still know very little about the inner workings of YouTube and other major platforms. Without endangering user privacy or proprietary trade secrets, YouTube could win greater public trust and better inform political debates if, for the first time, it explained the specific criteria its algorithms use to rank, recommend, and remove content—as well as how often and why those criteria change and how they are weighted relative to one another. To what degree, for example, have product designers prioritized user engagement, a factor that can lead to the amplification of content that stokes anger and fear? What attributes are likely to cause a video to “go viral”? And beyond the 2019 recalibration of the platform’s recommendation system, what mechanisms have designers incorporated to slow virality if there are indications that content could stir ethnic animosity or incite violence? Other topics that deserve more sunlight include the size and nature of YouTube’s content moderation corps. The company has resisted revealing basic information such as the proportion of reviewers who are outsourced, meaning they are not directly employed by YouTube but instead by third-party contractors. As we discuss in more detail in recommendation 3, outsourced workers are less likely to be effective in this critical function because they do not receive direct supervision from senior YouTube employees and executives. 2 Facilitate greater access to data that researchers need to study YouTube The video-sharing platform has not provided researchers with the sort of data access that, for example, Twitter has. To do more thorough empirical studies, researchers have told us that they need more information via YouTube’s API, or application programming interface. Currently, YouTube provides access only to content and metadata that are available at the time researchers connect to the API. To understand how a given video gained attention over time, they need access to historic data as well. Social scientists tell us that another potentially fruitful feature would be the ability for researchers to retrieve random samples of YouTube content, a need that may arise when a given search query otherwise returns an unmanageable number of results. Random sampling would allow researchers to make inferences from a subset of data and would better support the tracking of important trends. Some disclosures go beyond data access via the API. At present, YouTube doesn’t systematically disclose when it makes policy changes that may bear on the availability of problematic content. We understand that YouTube currently is in touch with certain academic researchers about these issues, and we hope this contact leads to progress. Researchers and the public at large would benefit from a greater understanding of how the platform functions. 3 Expand and improve human review of potentially harmful content The greater transparency discussed in the first two recommendations would help clarify how YouTube can expand and improve its content moderation system, especially in the design and operation of the automated filtering responsible for the vast majority of video removals. But it’s a safe bet that the company also can do a better job deploying the human reviewers who are essential to the policing of the platform. Their role is critical because machines typically lack the ability to distinguish between, say, the glorification of Nazism, which should be removed, and legitimate historical or satirical material about Nazism—a distinction that YouTube’s algorithm has at times struggled with.88 This is a massive task that will require Google to invest significantly greater resources, especially in countries in the Global South. Given that YouTube users watch a billion hours of video a day, the company needs more than 20 HOW YOUTUBE SPREADS HARMFUL CONTENT – AND WHAT CAN BE DONE ABOUT IT