CS 440/ECE 448
Fall 2018
Margaret Fleck
Midterm 1 skills list
Historical trivia
What were the following (in just a couple words)?
When and where were they developed?
- Shakey and Blocks world
- Waltz line labelling
- STRIPS
Search
You've done an MP on this, so can be expected to answer quite
detailed questions, e.g about A*.
Key examples: graph search, maze search, Missionaries and Cannibals puzzle.
8-puzzle
Basic search methods
- Search problem formulation: initial state, actions, transition model, goal state(s),
path cost, state space
- Outline for search algorithms: frontier, explored (done) states, best
path, avoiding loops, storing or reconstructing return path
- Uninformed search strategies: breadth-first, uniform cost search,
depth-first, iterative deepening, bidirectional
Edit distance (problem and algorithm)
A* search
- basic definitions and algorithm
- definitions of admissible and consistent, how do they relate? why
is consistency useful?
- returns optimal path if heuristic admissible
- what makes one heuristic better than another?
- greedy search: how does it differ from A*? how can it fail?
- weighted A*
Comparison of search methods
- Advantages and disadvantages of each of these search methods compared
to the others
Constraint satisfaction problems
Key examples (be familiar with basic rules)
- n-queens, map/graph coloring, Sudoku, Cryptarithmetic, Waltz line labelling
- Graph coloring is NP-complete.
Backtracking search (DFS)
- Variable assignments can be done in any order, search is to a known depth
- Why isn't looping a worry?
- Heuristics for variable and value selection:
most constrained/most constraining variable, least constraining value
- Forward checking, constraint propagation
- AC-3 algorithm
Hill-climbing
- how it works (high-level idea only)
- how it differs from backtracking search
Planning
- State and action representation
- Preconditions and effects (postconditions)
- Situation space vs. plan space planners
- Forward and backward planning
- Sussman anomaly, interleaved planning
- Partial order planning: the idea, plan modification operations
- The Frame Problem
- Towers of Hanoi takes time exponential in input size (number of rings)
Configuration space
You've done an MP on this, but the math/geometry turns evil very fast.
So expect concrete 2D problems involving relatively simple situations.
- Example configuration spaces: circular robot, n-link arm,
rectangular robot with/without rotation.
- Sketch, or answer questions about,
the configuration space for a (very simple) robot motion planning problem.
General knowledge (i.e. superficial only)
- types of robots (e.g. arms, moving carts, snakes, ...)
- ideal robot path: short but also smooth, safe
- graph-based planning: visibility graphs, cell decompositions, generalized
Voronoi diagrams
Probability
The MP for this is still in the future. So expect straightfoward questions about
definitions and proving very simple lemmas.
- Random variables, axioms of probability
- Joint, marginal, conditional probability
Naive Bayes (basic definitions only)
The MP for this is still in the future. So expect straightfoward questions about
definitions and proving very simple lemmas.
- Bayes rule
- Likelihood, prior, posterior
- argmax operator
- Maximum a posteriori (MAP) esimate, Maximum likelihood (ML) estimate,
factoring out P(evidence)
- How does prior affect these estimates?
- Independence and conditional independence
- Basic Naive Bayes model: suppose we have several conditionally independent
pieces of evidence, how do we combine these to calculate
P(cause | evidence)? (Just the main equation.)
Not on exam
The following material is
NOT ON THIS EXAM
Items that won't be covered:
- Historical survey material, except where explicitly noted above
Items that will be on midterm 2 (even though they may have been partly
covered in lecture before midterm 1).
- Further details of Naive Bayes, esp. anything to do with implementation
details.
- Bayes networks