Interview questions / Data Scientist
Data Scientist interview questions
These are questions Data Scientist candidates often hear, with a short note on what a strong answer covers. Reading them helps; saying your answers out loud helps more.
How would you explain a p-value to a manager with no stats background?
Use plain words and an example; show you know what it does not mean.
Design an A/B test for a new checkout button.
Cover the metric, sample size, test length, randomisation and what result would change the decision.
Your model has 95% accuracy. Is that good?
Ask about class balance and the cost of errors; mention precision, recall and a baseline.
How do you handle missing data?
Explain why data is missing first, then options: drop, impute, or model it, with trade-offs.
Tell me about an analysis that changed a decision.
Use STAR and name the decision and the result.
How do you prevent overfitting?
Mention a held-out test set, cross-validation, simpler models and regularisation.