You are interviewing for a Senior Data Scientist role. Answer the following statistics questions clearly and precisely:
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How would you explain a p-value to a Product Manager (PM) in plain language?
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What is the formal definition of a p-value?
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How should a p-value be interpreted? What are common misinterpretations?
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If you run an A/B test and obtain p = 0.03 for the primary metric, how would you make a decision? What additional context would you request before shipping?
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In a linear regression that includes potential confounders, how do you interpret each coefficient? What does “controlling for other variables” mean, and when can that interpretation fail?
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When and why would you use L1 (Lasso) vs L2 (Ridge) regularization? Describe practical tradeoffs and how you would select the regularization strength.