Lesson 19/100

Tutorials ML.NET Tutorial

Evaluation Metrics — Complete Guide

Evaluation Metrics — Complete Guide: free step-by-step lesson with examples, common mistakes, and interview tips — part of ML.NET Tutorial on Toolliyo Academy.

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ML.NET Tutorial · Lesson 19 of 100

Evaluation Metrics

FoundationsModelsNLP & advancedMLOps

Foundations · 1 — Context & data · ~6 min · Module 2: Machine Learning Basics

What is this?

Metrics quantify model quality — AUC/F1 for classification, MAE/R² for regression, NDCG for ranking.

Why should you care?

AIPredict go-live needs numbers, not “looks good in a demo”.

See it live — copy this example

Use a .NET console or Web API project with Microsoft.ML. Run dotnet run after pasting.

var metrics = ml.BinaryClassification.Evaluate(predictions);
Console.WriteLine($"AUC={metrics.AreaUnderRocCurve:F3} F1={metrics.F1Score:F3}");

What happened?

  • Pick metrics that match the business cost of errors.
  • Log them with model version.

Practice next

  1. Evaluate binary AUC/F1.
  2. Evaluate regression MAE.
  3. Store metrics JSON next to zip.
  4. Print confusion matrix.
  5. Compare two trainers on same split.

Remember

Right metric family. Business cost. Version + metrics.

AIPredict metric gate

CI fails if AUC < 0.85.

Outcome: Bad models never deploy.

Interview prep for this lesson

Practice these questions aloud after reading—each links to a full structured answer.

Junior Detailed
Explain Concepts in the context of ML.NET.
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define Concepts…
Mid Detailed
What are common mistakes teams make with LLMs when using ML.NET?
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define LLMs in p…
Senior Detailed
How would you debug a production issue related to RAG in a ML.NET application?
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define RAG in pl…
Junior Detailed
Describe a real-world scenario where Production mattered in a ML.NET project.
Short answer: Interviewers want a crisp definition, a practical example from your projects, and awareness of trade-offs—not textbook dumps. Explain a bit more How to structure your answer (60–90 seconds) Define Productio…
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ML.NET Tutorial
Course syllabus
Module 1: ML.NET Foundations
Module 2: Machine Learning Basics
Module 3: ML.NET Pipelines
Module 4: Classification Models
Module 5: Regression Models
Module 6: Recommendation Systems
Module 7: NLP with ML.NET
Module 8: Advanced ML.NET
Module 9: ASP.NET Core AI Integration
Module 10: MLOps & Cloud AI
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