Based on the book by Kim Scott, Radical Candor is about caring personally while challenging directly. It is advice for leaders but can be used by anyone in the workplace. It identifies behaviors (not personality types) and communication intentions in the moment of feedback or, as Scott prefers, guidance.
The most effective guidance is given in the top right quadrant. It is said so the the person getting it hears it -with both compassion or the intent to help and directly and clearly. Scott's main example is when her boss gave her feedback that she said "um" too much in a presentation. She brushed it off thinking the rest of her presentation and the strong results she was sharing spoke for her. Her boss then reframed it and told her directly "when you say 'um' every third word it makes you sound stupid". That got her attention and that is radical candor. Here is a summary so you can assess and identify the other four categories:
Obnoxious Aggression: A boss who will challenge and criticize but does not genuinely care about the employees or the outcomes. Praise feels insincere and criticism isn’t delivered respectfully or kindly.
Ruinous Empathy: A boss who genuinely cares but does not challenge their employees to improve. This person offers vague but sincere “surface level” praise and either offers no criticism or sugar coated and unclear (read useless) criticism.
Manipulative Insincerity: A boss who neither cares nor challenges. Offers non-specific praise that comes across as fake and offers criticism that is neither constructive nor kind.
Radical Candor: This is the goal! A healthy mix of genuine praise and constructive criticism that is delivered kindly and respectfully.
Once you have identified these areas, you can use them to determine what kind of leader your boss is which you can use to make a decision about your career, to use your power and influence skills with or to help you manage up. Most importantly, if you manage a team, assess your own guidance and communication and try to get to radical candor if you want a high-trust and high-performing team.