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Free guided course · ML 101

Learn how models learn. Test what they know.

A free guided machine-learning course covering data, training, evaluation, generalization and deployment, with worked examples, local audio and scored checkpoints.

Beginner · 6 lessons · 18 questions · About 48 minutes · No account needed

  • ML 101
  • Practical examples
  • Self-paced learning

“I believe AI is part of our future, and everyone should have free access to learn it. These courses are free, open to everyone, and never require an account.”

— Herb Trevathan, HerbDev

Your learning progress

0 of 6 checkpoints complete · Best score: 0 of 18

0 of 6

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Answer all three questions correctly to complete a checkpoint. Retry as often as you like; your best score counts. Scores stay on this browser and can be cleared. They do not transfer between devices.

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A clear place to begin

Start here directly, or take AI 101 first. No coding required; optional examples use simple arithmetic.

  • Identify features, labels and sensible dataset splits.
  • Explain training, loss, overfitting and common evaluation measures.
  • Plan a reproducible model experiment around real operating conditions.
Your path through each lesson
  1. Read or listen
  2. Explore a HerbDev example
  3. Try a small exercise
  4. Check, learn and retry

Learning is the point

There is no paywall, sign-up form or required purchase. All six lessons are available from the start. Use the scores to notice gaps in your understanding, then revisit an explanation and try again.

Vocabulary words have definitions on hover or keyboard focus, and links open their vocabulary entries. Every lesson includes a worked exercise, an answer guide and text alongside its audio.

Put it into practice · About 30 minutes

Plan and evaluate a small review classifier

Write a short experiment plan for a hypothetical classifier that flags images for human review. No coding, dataset download or paid tool is required. Your deliverable is a task definition, a data-splitting plan, a calculation sheet and a decision about what to test next.

Listen to the project brief

Read the project audio transcript

ML 101. Final practical project. Plan and evaluate a small review classifier. Write a short experiment plan for a hypothetical classifier that flags images for human review. No coding, dataset download or paid tool is required. Your deliverable is a task definition, a data-splitting plan, a calculation sheet and a decision about what to test next. HerbDev example. Use OrganicVision to think about how image analysis fits into a mobile workflow. The review classifier and counts below are invented teaching examples. They are not OrganicVision performance results. Your checklist. Define “needs review” as the positive class and describe how a human would assign that label. Keep related images from the same capture session together when splitting training, validation and test data. Write down an always-negative baseline and why accuracy alone could make it look useful. Calculate accuracy, precision and recall for 8 true positives, 4 false positives, 2 false negatives and 86 true negatives. Choose the more costly mistake for your hypothetical workflow and explain how that affects your metric choice. Specify one next experiment using validation data, keeping the test set out of repeated tuning. Pause the audio and work through the checklist. A worked solution is available on the course page. Could a teammate reproduce your calculations and explain why you chose that metric? Check the worked solution after you try. This planning exercise is separate from the scored checkpoints and is not a production-readiness certificate.

From idea to a checked result
  1. Define the label and baseline
  2. Split independent examples
  3. Evaluate a held-out test set
  4. Choose the next experiment
Your project checklist

Use the checklist to review your work. Saving uses the same cookie preference as course scores.

Compare with a worked solution

Task, split and baseline

The positive label means a reviewer should inspect the image; it is not a medical or safety diagnosis. Split by capture session before fitting any preprocessing to the training set. With 10 positive cases among 100 examples, an always-negative baseline has 90% accuracy and 0% recall. It misses every case that needs review.

Check the arithmetic

Accuracy is (8 + 86) / 100 = 94%. Precision is 8 / (8 + 4), about 67%. Recall is 8 / (8 + 2) = 80%. The classifier catches eight of ten positive cases, misses two, and sends four negative cases for unnecessary review. All four counts matter when comparing it with the baseline.

Choose a defensible next step

If missed positive cases are more costly than extra reviews, investigate whether a lower decision threshold improves recall on validation data while keeping review volume manageable. Record the threshold, metric and tradeoff before the final test evaluation. A single small test set does not establish reliable production performance; examine errors and gather representative independent examples.

Could a teammate reproduce your calculations and explain why you chose that metric? Check the worked solution after you try. This planning exercise is separate from the scored checkpoints and is not a production-readiness certificate.

Choose your next learning step →

Review missed questions

Revisit questions missed on your latest checkpoint attempts. These short reviews help you practise; they do not change your best checkpoint scores. Return to the lesson checkpoint when you are ready.

Check a lesson’s answers to build your review list. Saved reviews are available after cookie acceptance.

Keep exploring: What next? · AI vocabulary · AI 101 · Learning hub

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“Remove my test data” clears all AI 101 and ML 101 scores, reviews, project checklists and rating selections, plus saved vocabulary and recent history in this browser. Test entries cannot be separated from other learning progress. Cookie preferences, security protections, submitted feedback, contact emails and past analytics are kept.