F1 Score

Term from Machine Learning industry explained for recruiters

The F1 Score is a way to measure how well a machine learning model is performing its job. Think of it like a report card that combines two important aspects: how accurate the model is at finding what we're looking for (precision) and how many important things it manages to catch (recall). This single number helps employers understand if a candidate knows how to evaluate and improve AI models properly. It's particularly important when dealing with situations where both false positives and false negatives matter, like in fraud detection or medical diagnosis systems.

Examples in Resumes

Improved customer churn prediction model achieving F1 Score of 0.85

Evaluated multiple fraud detection algorithms using F1 Score and ROC curves

Optimized marketing response models reaching F1-Score of 0.92

Typical job title: "Machine Learning Engineers"

Also try searching for:

Data Scientist ML Engineer AI Engineer Machine Learning Developer Data Analytics Engineer AI/ML Specialist Machine Learning Researcher

Where to Find Machine Learning Engineers

Example Interview Questions

Senior Level Questions

Q: When would you choose F1 Score over accuracy as a metric?

Expected Answer: A senior candidate should explain that F1 Score is better for unbalanced datasets, like fraud detection where there are few fraud cases compared to normal transactions. They should give real-world examples and explain why this matters for business outcomes.

Q: How would you improve a model's F1 Score?

Expected Answer: Should discuss practical approaches like data balancing, feature engineering, and threshold adjustment, explaining these in business terms and their impact on the final results.

Mid Level Questions

Q: Can you explain what makes up the F1 Score?

Expected Answer: Should be able to explain that F1 Score combines precision (accuracy of positive predictions) and recall (ability to find all positive cases) in an understandable way, using real-world examples.

Q: What's a good F1 Score for a model?

Expected Answer: Should explain that it depends on the specific problem and industry, giving examples of acceptable scores in different situations and how they relate to business goals.

Junior Level Questions

Q: What is the F1 Score used for?

Expected Answer: Should be able to explain that it's a way to measure how well a model performs by combining accuracy and completeness into a single number.

Q: How do you calculate an F1 Score?

Expected Answer: Should understand that it's calculated from precision and recall, and be able to use basic tools and libraries to compute it, even if they don't remember the exact formula.

Experience Level Indicators

Junior (0-2 years)

  • Basic understanding of model evaluation metrics
  • Can calculate and interpret F1 Scores
  • Familiar with common ML libraries
  • Basic model training and evaluation

Mid (2-4 years)

  • Choosing appropriate evaluation metrics
  • Handling imbalanced datasets
  • Model optimization techniques
  • Performance analysis and reporting

Senior (4+ years)

  • Advanced model evaluation strategies
  • Custom metric development
  • Business impact assessment
  • Team guidance on metric selection

Red Flags to Watch For

  • Unable to explain when F1 Score is more appropriate than simple accuracy
  • No experience with imbalanced datasets
  • Lack of understanding about business implications of model metrics
  • Cannot explain model evaluation in simple terms