“First impressions are critically important in job interviews,” writes Baum in this compact introduction to the subject, “when we have only a short time to make our best impression.” Readers who have ever sat for interviews have probably wondered if they were making one of a number of possible mistakes in subtext or signaling. The author seeks to illustrate some of those errors through a series of fictionalized characters designed to embody what not to do and who not to be. Readers meet “The Interrupter,” who’s always interjecting opinions and reactions, and Baum gives the common-sense warning: “People don’t like to be interrupted.” Readers meet “The Messy Dresser,” who shows up with wrinkled clothes and such, and again, there’s a wise warning: “Whether it is fair or not, people make assumptions about you and your skills based on your appearance.” And there’s “The Nodder,” who nods and mutters “uh-huh” no matter what’s being said, which can lead to mixed signals: “A disconnect between the message your body language sends and the words you use can make one appear to be dishonest or false.” The author adds enormous value to these insightful categories by including in each case a passage of advice for the poor interviewees who may recognize themselves in the descriptions. Baum also delivers tips for interviewers, first analyzing whether or not the trait is a deal-breaker. The author then lays down the hard facts, the “Know When It’s Over” that means the attribute is, in fact, a deal-breaker. Thanks to Baum’s experience as an executive for Capital BlueCross and vivid imagination, these fictional stand-ins cover virtually everything that could go wrong in an interview, from talking too much and name-dropping to being overly familiar or artificially casual. And the tone throughout—sharp but not unsympathetic—will be bracingly useful to interviewers and interviewees alike.