AI Workbench · Level 2 of 15
Train and evaluate without leakage
Level 2 of 15 in the AI Workbench: a free AI exercise at Foundation level, which takes about 25 minutes. Train a churn model, reach the target score on validation, and look at the test set once.
Free · no download · about 25 minutes. Your work is saved on this device. Updated 18 Oct 2026.
The brief
- Client
- Larkfield Telecom (fictional, hosted by OFORO)
- Site
- OFORO data desk
- Work order
- OFR-WO-102
- Data set
- Customer churn
- Task code
- AIW-02
- Difficulty
- Foundation
- Type of work
- Modelling
Train a churn model, reach the target score on validation, and look at the test set once.
Skills you practise
- Train/validation/test split
- Logistic regression
- F1 score
- Data leakage
What the test checks
The acceptance test marks the skills this level practises.
- Train/validation/test split
- Logistic regression
- F1 score
- Data leakage
In this lab
- Train models in your browser
- Vision inspection, prompts, RAG and safe agents
- Check the AI's work before you trust it
Levels in the AI Workbench
Previous: Data health checkNext: Choose the metric and the threshold
- Data health check
- Train and evaluate without leakage
- Choose the metric and the threshold
- Overfitting: tune the tree
- Vision inspection on the conveyor
- Prompt to spec
- Answers with sources
- A safe agent
- Fairness check
- Privacy first
- Check the AI's work: finance
- Check the AI's work: HR
- Check the AI's work: marketing
- Check the AI's work: healthcare
- Check the AI's work: project management
Part of the AI Workbench
Prepare data, train a model and check the AI's work against a brief.
Feeds these internships: AI and Machine Learning, Data Science and Analytics, Generative AI and Prompt Engineering, AI Agents and Automation, Computer Vision, AI for Finance and Accounting, AI for HR and Recruitment, AI for Digital Marketing and Content, AI in Healthcare and Pharma, AI for Project Management.