What is survivorship bias in metrics?
PICTURE THIS: OVERFITTING
Simple meaning
You only analyze winners still visible — failed cases disappear.
WHY — Bias instead of guessing?
Why interviewers care about Bias:
who only read docs from people who shipped.
and tied to Data Science work.
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:
- 1You only analyze winners
still visible — failed cases disappear.
- 2Churned users missing from
surveys are an example.
- 3I ask what data
is absent.
- 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
You only analyze winners still visible — failed cases disappear. Churned users missing from surveys are an example.