What is the ideal Praise to Criticism ratio?

Which is more effective in improving team performance: using positive feedback to let people know when they’re doing well, or offering constructive comments to help them when they’re off track?

Research suggests top performing teams give each other more than 5 positive comments for every opportunity for improvement. Medium performing teams had a 2:1 ratio of positive to negative. Low performing teams had 3 negative comments for every positive one.

What happens in your team? And what do you role model?

This link to an HBR article explores this issue further.