Air India ml engineer Interview Questions and Answers

Regression models can be evaluated using R squared and adjusted R squared to measure the goodness of fit.

• R squared measures the proportion of the variance in the dependent variable that is predictable from the independent variables.

• Adjusted R squared adjusts for the number of predictors in the model, providing a more accurate measure of goodness of fit.

• R squared can be artificially inflated by adding more predictors, while adjusted R squared penalizes for adding unnecessary v...read more

Explanation of bagging, boosting, ensemble models, handling overfitting, and precision-recall-ROC curve.

• Bagging (Bootstrap Aggregating) involves training multiple models on different subsets of the training data and combining their predictions through averaging or voting.

• Boosting involves training multiple models sequentially, with each model correcting the errors of its predecessor.

• Ensemble models combine multiple individual models to improve overall performance and generali...read more

Decision trees are a popular machine learning algorithm used for classification and regression tasks.

• Decision trees are a flowchart-like structure where each internal node represents a feature or attribute, each branch represents a decision rule, and each leaf node represents the outcome.

• To select parent and child nodes, the algorithm calculates the best split at each node based on criteria like Gini impurity or information gain.

• Gini impurity is a measure of how often a rando...read more

Correlation measures the strength and direction of a relationship between two variables. A correlation of 0 indicates no linear relationship.

• Correlation measures the degree to which two variables move in relation to each other. It ranges from -1 to 1.

• A correlation of 0 means there is no linear relationship between the variables. They are not related in a linear fashion.

• For example, if the correlation between hours of study and exam scores is 0, it means there is no linear rel...read more

Creating dictionary in Python from 2 lists, using window functions and joins in SQL

• To create a dictionary in Python from 2 lists and key values, you can use the zip() function

• Example: dict(zip(keys_list, values_list))

• For SQL window functions like Rank(), you can use the OVER() clause

• Example: SELECT column1, column2, RANK() OVER(ORDER BY column3) AS rank_column FROM table_name

• For SQL joins, you can use INNER JOIN, LEFT JOIN, RIGHT JOIN, or FULL JOIN depending on the requiremen...read more