Comments on Assignment/PS 2

The assignment was graded out of 30 points. (We will normalize the grades for the problem sets at the end.)

• Software Lab = 12 points
  • Question 1 (Function composition) = 1 point
    The most common error was neglecting to answer all or some of the test case questions.
  • Question 2 (Summation) = 1 point
    A common error was incrementing the counter by 1 in both cases.
  • Question 3 (Using Newton's method) = 1 point
    A common error was neglecting to "try it for other positive values of x."
  • Question 4 (Defining sets) = 1 point
    Define both finite and infinite sets.
  • Question 5 (setUnion and setIntersection) = 2 points
    "What could you evaluate now, to demonstrate that your definition produces the correct set?" This means provide test cases for your code.
  • Question 6 (setComplement) = 1 point
  • Question 7 (setDifference) = 1 point
    Many people ignored the suggestion to try to use previously defined set operations.
  • Question 8 (Empty and universal sets) = 1 point
    Sets should be represented as functions that take an element and return a Boolean. Both the empty set and the universal set were required.
  • Question 9 (Newton's method with negative x) = 1 point
    A common error was failing to provide answers to the required test cases (-10, -100).
  • Question 10 (Sqrt of negative) = 1 point
  • Question 11 (Discard small imaginary) = 1 point
• Design Lab = 18 points
  • Question 19 (ifNDB) = 2 points
    The function ifNDB should take a condition and two behaviors as arguments (all of which are functions themselves), and return a function which takes sensors as an argument. A common error was neglecting to mention sensors at all.
  • Question 20 (prioritizedAnd of sets) = 1 point
  • Question 21 (prioritizedAnd returns empty set) = 1 point
  • Question 22 (prioritizedAndNDP) = 6 points
    3 points for the program, 2 points for explanation, and 1 point for testing. A common confusion on this problem was about the type of a behavior. A behavior is a function, not a set. When a behavior is applied to sensors, it returns a set of actions. It should not call doAction directly.
  • Question 23 (prioritzedAnd with noCrash and forward) = 2 points
    Describe the way in which you combined your behavior. Which was first in the list? How was the action selected from the allowed actions (selectAction or selectActionRandomly)? Then, given those design choices, how did the robot behave? How is the behavior explained by the code you wrote? Even better, explore the space of design choices a little bit and tell us how the choices effect behavior and why.
  • Question 24 (Three new behaviors) = 3 points
    1 point for each correctly implemented behavior.
  • Question 25 (Behavior combinations) = 1 point
    Use prioritizedAndNDB, ifNDB, orNDB or andNDB to combine multiple behaviors together.
  • Question 26 (Behavior testing) = 2 points
    Run your behaviors both in the simulator and on the robot. Describe what the robot does in both cases, and how the code you wrote explains that behavior. Write about differences between the simulated and real robots' behavior. If you don't understand your robot's behavior, either choose a less complicated set of behaviors to describe or ask someone for help.