I am confused whether to use f1 score with 'micro' average or 'macro' average for better evaluation. Given my dataset is highly imbalanced(600:100000)
To summarise this answer,
Macro calculates and F1 score for each class then averages them.
Micro calculates the recall/precision for each class, averages them then calculates the F1 score.
Micro average is preferable in a multi class situation where one class heavily outweighs the others.