This document discusses the challenges of testing machine learning and artificial intelligence algorithms. It describes the author's experience testing a new product at Comcast Advanced Advertising that used machine learning to intelligently deliver ads. Key challenges included a lack of experience with machine learning applications, stochastic output, computationally intense validation, and communication barriers with the data science team. The document outlines skills needed for machine learning testing, including statistics, terminology, tools, and methods. It emphasizes the importance of visualization, speaking the same language as data scientists, and addressing stakeholders' fears to build confidence in machine learning.