How can you tell that a model is overfitting?
PICTURE THIS: DATA SPLIT
Fit on train, tune on val, report on test once.
Simple meaning
Compare training metrics with validation metrics.
WHY — Overfitting instead of guessing?
Why interviewers care about Overfitting:
question about Overfitting.
trade-offs, and what you would actually do on a AI / ML project - not buzzwords.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Compare training metrics with
validation metrics.
- 2A large and growing
gap is the main warning sign.
- 3Learning curves that show
train error falling while validation error rises confirm the diagnosis.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Compare training metrics with validation metrics. A large and growing gap is the main warning sign.