To effectively evaluate your applicants' proficiency in Data Science, consider using these common interview questions. They will help you identify whether candidates possess the necessary skills and knowledge required for the role. For detailed insights into a Data Scientist's responsibilities, you can refer to data scientist job description.

1. Can you explain a data science project you have worked on from start to finish?
2. How do you handle missing or inconsistent data in a dataset?
3. What is overfitting, and how can you prevent it?
4. Can you explain the difference between supervised and unsupervised learning?
5. How do you choose the right algorithm for a particular problem?
6. What are some methods you use for feature selection?
7. What is the significance of cross-validation in model building?
8. Can you discuss a challenging data science problem you have encountered and how you solved it?
9. How do you communicate your findings and insights to non-technical stakeholders?
10. What tools and programming languages are you most comfortable with in data science?