Evaluation & Quality
Balanced accuracy
A score that gives each group equal importance when measuring how often it is correctly recognized.
Example
A test gives equal importance to recognizing rare and common groups.
Why people use it
It gives uncommon categories a fairer role in a combined accuracy score.
What you'll hear
“Don't let the larger group hide the missed cases.”
What this means for you
Choose a score that does not hide mistakes affecting less common cases.
Can you control it?
No
No direct control. This describes a wider issue, concept or result rather than something you can simply switch on or off in a tool.
Common questions
- Can balanced accuracy cover more than two groups?
- Yes. It can average how well each group is recognized across several possible groups.
- Can ordinary accuracy look good when this score is poor?
- Yes. Correctly guessing the common group can hide failure to recognize a rare group.
- Does it reflect the financial cost of mistakes?
- Not directly. Equal attention to categories is different from weighting mistakes by their consequences.