Data for AI Fundamentals

What is supervised learning in machine learning?

• Learning without labeled data

• Learning with labeled data

• Learning with a mix of labeled and unlabeled data

• Learning from the structure of the input data

Answer explanation

Supervised learning involves training a model on a dataset that includes input-output pairs, meaning the data is labeled. The model learns to map inputs to outputs based on this labeled data.

Which algorithm is commonly used for classification tasks?

• Linear Regression

• K-Nearest Neighbors (KNN)

• K-Means Clustering

• Principal Component Analysis (PCA)

Answer explanation

K-Nearest Neighbors (KNN) is a widely used algorithm for classification. It classifies a data point based on how its neighbors are classified. When a new, unlabeled instance needs to be classified, the KNN algorithm identifies the 'k' training instances that are closest to this new instance. The closeness is typically measured using distance metrics such as Euclidean distance.

What is overfitting in machine learning?

• When a model performs well on training data but poorly on test data

• When a model performs well on both training and test data

• When a model performs poorly on training data but well on test data

• When a model performs poorly on both training and test data

Answer explanation

• Overfitting occurs when a model learns the details and noise in the training data to an extent that it negatively impacts its performance on new, unseen data. This means the model has become too complex and specific to the training data.

Which metric is used to evaluate a regression model?

• Accuracy

• Precision

• Recall

• Mean Squared Error (MSE)

Answer explanation

• Mean Squared Error (MSE) is a common metric for evaluating regression models. It measures the average squared difference between the actual and predicted values, giving an idea of how well the model's predictions match the true values.

What is the primary data structure used in pandas for 2-dimensional labeled data?

• Series

• DataFrame

• Dictionary

• Array

Answer explanation

A DataFrame is a two-dimensional, size-mutable, and potentially heterogeneous tabular data structure with labeled axes (rows and columns) in pandas. It is similar to a table in a database or an Excel spreadsheet.

How do you read a CSV file into a pandas DataFrame?

• • pd.load_csv('file.csv')

• pd.read_csv('file.csv')

• pd.open_csv('file.csv')

• pd.import_csv('file.csv')

Which method is used to display the first few rows of a pandas DataFrame?

• df.head()

• df.tail()

• df.first()

• df.show()

What function is commonly used to create a line plot in matplotlib?

• plt.scatter()

• plt.bar()

• plt.plot()

• plt.hist()

Which command is used to display a plot in matplotlib?

• plt.display()

• plt.show()

• plt.draw()

• plt.render()

How can you add a title to a plot in matplotlib?

• plt.label('Title')

• plt.name('Title')

• plt.title('Title')

• plt.caption('Title')