Question

Which of the following can be useful for diagnosing data entry errors?

(a) hat values

(b) dffit

(c) resid

(d) all of the mentioned

The question was asked in a national level competition.

This intriguing question comes from Residual Variation and Multivariate in chapter Statistical Inference and Regression Models of Data Science

Answer 1

Right choice is (a) hat values

To explain I would say: resid returns the ordinary residuals.