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May 2024 term · Reinforcement Learning · BSDA5007

Reinforcement Learning Quiz 2: 4 August 2024 (May 2024 term)

The IIT Madras BS Reinforcement Learning (Reinforcement Learning) Quiz 2 paper sat on 4 Aug 2024, in the May 2024 term: 16 questions for 40 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.

Questions
16
Marks
40
Duration
120 min
Numerical
6
MCQ
10

Updated

Official paper: IIT M DEGREE AN EXAM QDB2 4 Aug 2024 · No negative marking.

Question 1

+2 marksNumerical answer

Based on the above data, answer the given subquestions.

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Correct answer: 3.5 (accepted within ±0.05)

Question 2

+2 marksNumerical answer

Based on the above data, answer the given subquestions.

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Correct answer: 3 (accepted within ±0.05)

Question 3

+4 marksNumerical answer

Based on the above data, answer the given subquestions.

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Correct answer: 8.1 (accepted within ±0.05)

Question 4

+4 marksNumerical answer

Based on the above data, answer the given subquestions.

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Correct answer: 0.145 (accepted within ±0.005)

Question 5

+3 marksNumerical answer
Show answer

Correct answer: 5.525 (accepted within ±0.075)

Question 6

+3 marksNumerical answer
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Correct answer: 8.36 (accepted within ±0.05)

Question 7

+2 marksOne correct option
  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • C

Question 8

+2 marksOne correct option
  1. A

    The eligibility trace is used to store past observations and actions.

  2. B

    The eligibility trace determines the learning rate for updating the value estimates.

  3. C

    The eligibility trace helps in determining which state-action pairs are eligible for updates.

  4. D

    The eligibility trace maintains a history of rewards received in each state.

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Correct answer

  • C

    The eligibility trace helps in determining which state-action pairs are eligible for updates.

Question 9

+2 marksOne correct option

What is a key advantage of using n-step TD prediction over one-step TD prediction?

  1. A

    n-step TD prediction requires less memory and computational resources.

  2. B

    n-step TD prediction can handle delayed rewards and credit assignment over multiple time steps.

  3. C

    n-step TD prediction converges faster to the optimal policy.

  4. D

    n-step TD prediction guarantees convergence to the optimal value function for any choice of the learning rate.

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Correct answer

  • B

    n-step TD prediction can handle delayed rewards and credit assignment over multiple time steps.

Question 10

+2 marksOne correct option

Consider a reinforcement learning agent navigating a complex environment with sparse rewards. Which of the following statements accurately describes a key advantage of using Double Q- learning in this scenario?

  1. A

    Double Q-learning helps to reduce the variance in action value estimates, leading to more stable learning.

  2. B

    Double Q-learning is guaranteed to converge to the optimal policy even with non-linear function approximation.

  3. C

    Double Q-learning requires fewer samples to achieve the same level of performance compared to traditional Q-learning.

  4. D

    Double Q-learning is less sensitive to hyperparameter tuning, making it easier to train in complex environments.

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Correct answer

  • A

    Double Q-learning helps to reduce the variance in action value estimates, leading to more stable learning.

Question 11

+2 marksOne correct option

What is a key advantage of using a target network in the Deep Q-Network (DQN) algorithm?

  1. A

    The target network helps to reduce the computational complexity of the Q- learning updates.

  2. B

    The target network prevents the algorithm from overfitting to the current Q- value estimates.

  3. C

    The target network stabilizes the learning process by providing a more consistent target for Q-value estimation.

  4. D

    The target network enables the agent to explore more efficiently by incorporating additional sources of information.

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Correct answer

  • C

    The target network stabilizes the learning process by providing a more consistent target for Q-value estimation.

Question 12

+2 marksOne correct option

In the context of Deep Q-Networks (DQN), how does experience replay contribute to improving learning efficiency?

  1. A

    Experience replay prioritizes important experiences based on their impact on the agent’s learning progress.

  2. B

    Experience replay reduces the computational complexity of the learning algorithm by storing only the most relevant experiences.

  3. C

    Experience replay mitigates the effects of non-stationarity in the data distribution by sampling uniformly from a replay buffer.

  4. D

    Experience replay breaks the temporal correlations in the data, allowing for more effective learning from past experiences

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Correct answer

  • D

    Experience replay breaks the temporal correlations in the data, allowing for more effective learning from past experiences

Question 13

+2 marksOne correct option

How does the choice of function approximator impact the performance of policy gradient methods?

  1. A

    The choice of function approximator has no impact on the performance of policy gradient methods, as long as it can represent the policy space accurately.

  2. B

    Deep neural networks are the only suitable function approximators for policy gradient methods due to their ability to handle high-dimensional state and action spaces.

  3. C

    The choice of function approximator affects the stability, convergence rate, and generalization capabilities of policy gradient methods.

  4. D

    Linear function approximators are always preferred over non-linear function approximators for policy gradient methods to ensure faster convergence.

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Correct answer

  • C

    The choice of function approximator affects the stability, convergence rate, and generalization capabilities of policy gradient methods.

Question 14

+2 marksOne correct option

How does the inclusion of a baseline in the REINFORCE algorithm impact its learning dynamics and performance?

  1. A

    Incorporating a baseline reduces the variance of the gradient estimates, leading to more stable and efficient learning.

  2. B

    Incorporating a baseline increases the computational complexity of the algorithm, making it slower to converge.

  3. C

    Incorporating a baseline improves the exploration capabilities of the algorithm by encouraging more diverse action selection.

  4. D

    Incorporating a baseline ensures that the algorithm converges to the optimal policy more quickly by reducing the bias in the gradient estimates.

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Correct answer

  • A

    Incorporating a baseline reduces the variance of the gradient estimates, leading to more stable and efficient learning.

Question 15

+3 marksOne correct option

In Dueling DQN, what is the primary advantage of decoupling the value function into state values and advantage values?

  1. A

    Decoupling the value function allows for more efficient computation of Q- values, reducing the computational complexity of the algorithm.

  2. B

    Decoupling the value function facilitates better exploration by explicitly separating the estimation of state values and advantage values.

  3. C

    Decoupling the value function enables Dueling DQN to learn state values more accurately, leading to improved stability during training.

  4. D

    Decoupling the value function allows Dueling DQN to better handle scenarios where certain actions are consistently advantageous or disadvantageous across states.

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Correct answer

  • D

    Decoupling the value function allows Dueling DQN to better handle scenarios where certain actions are consistently advantageous or disadvantageous across states.

Question 16

+3 marksOne correct option

In reinforcement learning, what distinguishes the semi-gradient method from the full gradient method?

  1. A

    The semi-gradient method uses only a subset of the available data to compute parameter updates, while the full gradient method uses all available data.

  2. B

    The semi-gradient method updates the parameters of the value function based on a mixture of TD error and the gradient of the value function, while the full gradient method updates parameters using only the gradient.

  3. C

    The semi-gradient method is more computationally efficient than the full gradient method, requiring fewer iterations to converge to the optimal solution.

  4. D

    The semi-gradient method guarantees convergence to the optimal policy for any choice of learning rate, while the full gradient method may diverge with certain learning rates.

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Correct answer

  • B

    The semi-gradient method updates the parameters of the value function based on a mixture of TD error and the gradient of the value function, while the full gradient method updates parameters using only the gradient.