Micro-Macro Precision,Recall and F-Score

Ramit Pahwa
2 min readSep 25, 2017

--

I was always mix-up precision and recall and this messes up things more times the you can imagine !!.So thought of writing a short post to summarize an easy interpretable definition of the following terms:

Precision

Recall

F-Score

To understand the above we require the knowledge of True/False Positives and Negatives which can be easily be remembering the following confusion matrix

Confusion matrix

Now, that we get what True/False Positives & Negatives are we can formally define

Precision as fraction of true positive among all the positive’s recalled.

Recall as fraction of true positives among all the correct events.

F-Score (Balanced ) as the harmonic mean of the Precision and Recall

Micro Averaged metrics given two different set of data :

Macro Averaged metrics with two datasets :

USAGE:

Macro-averaged metrics are used when we want to evaluate systems performance across on different datasets.

Micro-averaged metrics should be used when the size of datasets are variable.

This is my first post ,hope you find it useful !! 😃

--

--