They are both powerful tools that compensate for each other and need to be balanced and traded off during the model building process. “The bitter lesson” in 30 seconds“The bitter lesson” is one of the most popular opinion pieces about AI research and it’s future. Counter-argumentNo machine learning model was ever built using pure “human knowledge” — because then it wouldn’t be a learning model. It’s possible that the sum total of investment in domain knowledge related tasks has not changed so dramatically over time. What may have changed is how this investment is distributed across the model building lifecycle.