ML 4 Classfn

What does the K in KNN stand for?

• Knowledge
• Number of Neighbors
• Kernel
• K-means

What is the primary function of the KNN algorithm?

• Clustering
• Dimensionality reduction
• Classification and regression
• Regression analysis

Which metric is used by KNN to classify a new data point?

• Cosine similarity
• Jaccard index
• Manhattan distance
• Euclidean distance

What is a key limitation of KNN?

• It requires labeled data
• It becomes slow with large datasets
• It is not interpretable
• It cannot handle numerical data

Which of the following is true about a Decision Tree?

• It uses distance-based classification
• It clusters data points
• It splits data based on information gain or Gini index
• It always results in linear models

How does a Random Forest improve over a single Decision Tree?

• By reducing input features
• By combining multiple trees for better accuracy
• By using distance measures
• By pruning branches

What does a Confusion Matrix represent?

• Clustering output
• Accuracy plot
• Summary of prediction results
• Loss function values

Which value in a confusion matrix shows the number of incorrectly predicted positive instances?

• True Positive
• False Positive
• True Negative
• False Negative

What does 'Precision' measure in classification?

• Correctly predicted positives out of all predicted positives
• All positives in dataset
• Overall model accuracy
• True positives out of actual positives

How is Recall calculated?

• TP / (TP + FN)
• FP / (FP + TN)
• TP / (TP + FP)
• TN / (TN + FP)