Learn Before
What is the minimum F1 score, and when does it occur?
Question: An evaluation report summarizes a classifier with precision and recall. Since F1 is the harmonic mean of those two values, what is the smallest possible F1 score, and what condition on precision or recall produces it?
Sample answer: The minimum F1 score is 0. This happens whenever either precision is 0 or recall is 0.
Key points:
- The lowest possible F1 value is 0.
- F1 becomes 0 if precision is 0 or recall is 0.
Rubric: The response must state that the minimum F1 score is 0 and explain that this occurs when precision or recall equals 0.
0
1
Tags
Data Science
Machine Learning
Deep Learning
Supervised Learning
Dive into Deep Learning @ D2L
Machine Learning Yearning @ DeepLearning.AI
Related
Which mean is used in the F1 score?
An F1 score of 1.0 means precision and recall are both perfect.
The F1 score is _____ when precision or recall is 0.
Match each F1-related term to the best description.
Order the steps for calculating an F1 score from precision and recall.
Why is the F1 score often used instead of the plain average of precision and recall?
An F1 score can still be misleading when one class is much more common, because it ignores true negatives.
The F1 score is often used in NLP tasks such as named entity recognition and _____ segmentation.
Match each F1 score property to the explanation that best fits it.
When to Use F1 Score
Why the F1 Score Is Useful, and Where It Falls Short
When F1 is a poor single metric for an imbalanced screening task
What is the minimum F1 score, and when does it occur?