Whether you do annual Performance Reviews or have adopted a process of regular ‘chats’ the title applies – Praise the person, criticise the behaviour.
It is possible to have a conversation about what they did, their behaviour, as something apart from their self. You can have a dispassionate discussion as to why the behaviour was not appropriate, not optimal. It is impossible to discuss what went wrong when the person feels attacked and threatened.
Conversely, when someone has done something well, praise the person for the behaviour. The balance makes a person feel more positive about their work, their manager and their employer, so they seek to achieve more positive feedback. Don’t forget “Praise the person, criticise the behaviour”!
I’d call that a win-win, wouldn’t you?