Which regression method assumes a linear relationship between the independent and dependent variables?
- Decision Tree Regression
- Logistic Regression
- Polynomial Regression
- Ridge Regression
Polynomial Regression assumes a linear relationship between the independent and dependent variables. It models relationships as polynomial functions, and other regression methods may assume different relationships.
A medical research company is working on image data, where they want to classify microscopic images into cancerous and non-cancerous categories. The boundary between these categories is not linear. Which algorithm would be a strong candidate for this problem?
- Convolutional Neural Network (CNN)
- Logistic Regression
- Naive Bayes Classifier
- Principal Component Analysis
Convolutional Neural Networks (CNNs) are excellent for image classification tasks, especially when dealing with non-linear boundaries. They use convolutional layers to extract features from images, making them suitable for tasks like cancerous/non-cancerous image classification.
The term "exploitation" in reinforcement learning refers to which of the following?
- Utilizing the best-known actions
- Trying new, unexplored actions
- Maximizing exploration
- Modifying the environment
Exploitation involves utilizing the best-known actions to maximize rewards based on current knowledge, minimizing risk and uncertainty.
________ learning is often used for discovering hidden patterns in data.
- Reinforcement
- Semi-supervised
- Supervised
- Unsupervised
Unsupervised learning is a machine learning approach where algorithms are used to identify patterns in data without explicit guidance. It is commonly employed for data exploration and pattern discovery.
When dealing with high-dimensional data, which of the two algorithms (k-NN or Naive Bayes) is likely to be more efficient in terms of computational time?
- Both Equally Efficient
- Naive Bayes
- Neither is Efficient
- k-NN
Naive Bayes is typically more efficient in high-dimensional data due to its simple probabilistic calculations, while k-NN can suffer from the "curse of dimensionality."
In the k-NN algorithm, as the value of k increases, the decision boundary becomes __________.
- Linear
- More complex
- More simplified
- Non-existent
As the value of k in k-NN increases, the decision boundary becomes more simplified because it is based on fewer neighboring data points.
A company wants to segment its customers based on their purchasing behavior. They have a fair idea that there are around 5 distinct segments but want to confirm this. Which clustering algorithm might they start with?
- K-Means Clustering
- Agglomerative Hierarchical Clustering
- Mean-Shift Clustering
- Spectral Clustering
The company might start with K-Means Clustering to confirm their idea of five distinct segments. K-Means is often used for partitioning data into a pre-specified number of clusters and can be a good choice when you have a rough idea of the number of clusters.
Variational autoencoders (VAEs) introduce a probabilistic spin to autoencoders by associating a ________ with the encoded representations.
- Probability Distribution
- Singular Value Decomposition
- Principal Component
- Regression Function
VAEs introduce a probabilistic element to autoencoders by associating a probability distribution (typically Gaussian) with the encoded representations. This allows for generating new data points.
t-SNE is particularly known for preserving which kind of structures from the high-dimensional data in the low-dimensional representation?
- Global Structures
- Local Structures
- Numerical Structures
- Geometric Structures
t-SNE is known for preserving local structures in the low-dimensional representation, making it effective for visualization and capturing fine-grained relationships.
When both precision and recall are important for a problem, one might consider optimizing the ________ score.
- Accuracy
- F1 Score
- ROC AUC
- Specificity
The F1 Score is a measure that balances both precision and recall. It is especially useful when you want to consider both false positives and false negatives in your classification problem.