The value at which the sigmoid function outputs a 0.5 probability, thereby determining the decision boundary in logistic regression, is known as the ________.

  • Decision Point
  • Inflection Point
  • Sigmoid Threshold
  • Threshold Value
The value at which the sigmoid function outputs a 0.5 probability is known as the decision point. This is the threshold value that separates the two classes in a binary logistic regression.

In which learning approach does the model learn to...

  • Reinforcement Learning
  • Semi-Supervised Learning
  • Supervised Learning
  • Unsupervised Learning
In reinforcement learning, a model learns by interacting with an environment and receiving rewards or penalties based on its actions. It aims to make decisions to maximize cumulative rewards.

What is the primary reason for using Random Forests over a single Decision Tree in many applications?

  • Faster training time
  • Increased accuracy
  • Lower memory usage
  • Simplicity
Random Forests are preferred due to their increased accuracy over single Decision Trees. They work by aggregating the predictions of multiple trees, which reduces overfitting and results in better overall performance.

Dimensionality reduction techniques, like PCA and t-SNE, are essential when dealing with the ________ curse.

  • Overfitting
  • Bias-Variance Tradeoff
  • Curse of Dimensionality
  • Bias
The "Curse of Dimensionality" refers to the increased complexity and sparsity of data in high-dimensional spaces. Dimensionality reduction techniques, such as PCA (Principal Component Analysis) and t-SNE, are crucial to mitigate the adverse effects of this curse.

A robot is navigating a maze. Initially, it often runs into walls or dead-ends, but over time it starts finding the exit more frequently. To achieve this, the robot likely emphasized ________ in the beginning and shifted towards ________ over time.

  • Exploration, Exploitation
  • Breadth-First Search
  • Depth-First Search
  • A* Search
In the context of reinforcement learning, the robot employs "exploration" initially to discover the maze, and as it learns, it shifts towards "exploitation" to choose actions that yield higher rewards, like finding the exit.

In reinforcement learning, the agent learns a policy which maps states to ________.

  • Actions
  • Rewards
  • Values
  • Policies
In reinforcement learning, the agent learns a policy that maps states to optimal actions, hence filling in the blank with "Policies" is accurate. This policy helps the agent make decisions in various states.

You are working on a dataset with a large number of features. While some of them seem relevant, many appear to be redundant or irrelevant. What technique would you employ to enhance model performance and interpretability?

  • Data Normalization
  • Feature Scaling
  • Principal Component Analysis (PCA)
  • Recursive Feature Elimination (RFE)
Principal Component Analysis (PCA) is a dimensionality reduction technique that can help reduce the number of features while preserving the most important information. It enhances model performance by eliminating redundant features and improves interpretability by transforming the data into a new set of uncorrelated variables.

Which term describes a model that has been trained too closely to the training data and may not perform well on new, unseen data?

  • Bias
  • Generalization
  • Overfitting
  • Underfitting
Overfitting is a common issue in machine learning where a model becomes too specialized to the training data and fails to generalize well to new data. It's essential to strike a balance between fitting the training data and generalizing to unseen data.

Which RNN architecture is more computationally efficient but might not capture all the intricate patterns that its counterpart can: LSTM or GRU?

  • GRU
  • LSTM
  • Both capture patterns efficiently
  • Neither captures patterns effectively
The GRU (Gated Recurrent Unit) is more computationally efficient than LSTM (Long Short-Term Memory) but may not capture all intricate patterns in data due to its simplified architecture. LSTM is more expressive but computationally demanding.

In the context of machine learning, what is the primary concern of fairness?

  • Bias
  • Overfitting
  • Underfitting
  • Feature Selection
The primary concern in fairness within machine learning is 'Bias.' Bias can lead to unequal treatment or discrimination, especially when making predictions in sensitive areas like lending or hiring.