ML 4 Classfn v2

What is the primary function of the KNN algorithm?

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

What does the K in KNN stand for?

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

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

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

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

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

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

What does a Confusion Matrix represent?

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

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

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

What does 'Precision' measure in classification?

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

How is Recall calculated?

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