Regression Diagnostics: An Introduction (Quantitative Applications in the Social Sciences Book 79) by John Fox provides a comprehensive introduction to methods for assessing the adequacy of regression models fit to data. The book covers two primary types of regression models: normal linear regression (LM), where the response variable is quantitative and assumed to follow a normal distribution given the values of explanatory variables, and generalized linear models (GLMs), in which the conditional distribution of the response variable belongs to an exponential family. This second edition offers insights into how regression diagnostics can reveal deficiencies in these models and suggest potential improvements. Accompanying R code and datasets for illustrative examples are available on a dedicated website.