Case Study: YouTube, Part 1 Back to: Building Recommender Systems with Machine Learning and AI Previous Lesson Temporal Effects, and Value-Aware Recommendations Lesson 11 within section Real-World Challenges of Recommender Systems. You must enroll in this course to access course content. Next Lesson Case Study: YouTube, Part 2 Lesson 2 within section Case Studies. You must enroll in this course to access course content.