17 More Must-Know Data Science Interview Questions and Answers, Part 2

Editor's note: See also part 1 of 17 More Must-Know Data Science Interview Questions and Answers. Overfitting is when you build a predictive model that fits the data "too closely", so that it captures the random noise in the data rather than true patterns. As a result, the model predictions will be wrong when applied to new data. We frequently hear about studies that report unusual results (especially if you listen to Wait Wait Don't Tell Me), or see findings like "an orange used car is least likely to be a lemon", or learn that studies overturn previous established findings (eggs are no longer bad for you). Many such studies produce questionable results that cannot be repeated.