What will be in the CPSC 422 Midterm (24 February 2005) **************************************************** We will have some subset (not necessarily strict subset) of the following questions: Question 1 (robot control) I will select one or two of the following questions (perhaps reworded). Use proper English. Be concise in your answers. You must use your own words (text from the textbook or another source copied onto your crib sheet will not get any marks). (a) Explain why we use hierarchical (layered) controllers. (b) What does it mean that the higher layers run at a different time scale than lower layers? (c) Give the intuition behind the notion of a transduction? Why do we define causal transductions? (d) Why does an agent have a state? (e) Explain why we need a command function and a state transition function in a robot controller but not other functions. (f) Explain how the communication between layers and communication between time steps is handled in the logical implementation of a hierarchical controller. (g) Why don't we run the logical specification of a hierarchical controller using SLD resolution? How can it be implemented efficiently? Question 2 (decision-theoretic planning) One or more of the following: Show how to do one step of value iteration. Explain the advantages and disadvantages of storing the Q function as compared to storing the Value function. Explain how decision-theoretic planning fits into the robot control architecture. How can a robot controller be built using decision-theoretic planning. Question 3 (reinforcement learning) One or more of the following: Show how to do one step of Q-learning, or the effect of a sequence of steps. Explain why SARSA(lambda) learns faster than Q-learning. Explain why alpha_k should be reduced as function of k. Explain why you may not want to reduce alpha. Explain how Q-learning fits into the robot control architecture. How can a robot controller be built using Q-learning? There are a number of parameters in SARSA-lambda: alpha, gamma, lambda. Explain what each does. Which one affects what is the correct answer? Which one affects whether it will converge? Question 4 (Assumption-based reasoning). One or more of the following: Find the conflicts and the consistency-based diagnoses for a particular example domain, (e.g., Exercise 7.1, or perhaps a more realistic example). find the abductive diagnoses or model a domain so you can find the abductive diagnoses. (e.g., exercise 9.1). a question about default prediction or about the combination of default and abductive reasoning. (What you should predict based on normality assumptions). Give a meta-interpreter for a particular example. Question 5 (Assignment) Some questions about what you should have learned from doing assignments. For example: Show how one step of value iteration, Q-learning, SARSA-lambda works for the game domain of assignment 2.