Brane Enterprises Data Scientist Interview Questions and Answers

Data Scientist interview questions on model building, random forest, ROC curve, gradient boosting, and real estate valuation

• For model building, I followed the CRISP-DM process and used various algorithms like logistic regression, decision trees, and random forest

• Random forest hyperparameters include number of trees, maximum depth, minimum samples split, and minimum samples leaf

• ROC curve is a graphical representation of...read more

To choose optimum probability threshold from ROC, we need to balance between sensitivity and specificity.

• Choose the threshold that maximizes the sum of sensitivity and specificity

• Use Youden's J statistic to find the optimal threshold

• Consider the cost of false positives and false negatives

• Use cross-validation to evaluate the performance of different thresholds

To test time series trend break up, statistical tests like Augmented Dickey-Fuller test can be used.

• Augmented Dickey-Fuller test can be used to check if a time series is stationary or not.

• If the time series is not stationary, we can use differencing to make it stationary.

• After differencing, we can again perform the Augmented Dickey-Fuller test to check for stationarity.

• If there is a significant change in the mean or va...read more

Communicate transparently and offer alternative solutions.

• Explain the limitations of the available data and the potential risks of making decisions based on incomplete information.

• Offer alternative solutions that can be implemented with the available data.

• Collaborate with the customer to identify additional data sources or explore other options to gather more data.

• Provide regular updates on the progress of data collect...read more