AI Class III, Homework I

Well, we finally got it, and it's not so scary, just a little vague... They posted a set of  seven short videos each posing a question with a multi-choice or small numeric answer. Unfortunately there are some ambiguities about the constraints and exact definitions in some of the problems. There are a couple useful discussion threads on the Reddit AICLASS site which are wrangling about the specifics:

• First Homework Posted
• Homework A* question

I have distilled and posted the Week 1 Homework questions and options, along with comments about the ambiguities encountered (mine and others from the reddit threads). Stay tuned for answers next week...

To get to the bottom of it we're really gonna just have to wait until we get clarification from on high. We hope we do anyway. As someone in those threads pointed out, this is the kind of stuff one would ask the TA or Prof if one were having a two-way class like experience.

<IMHO mode="I could be wrong about this">
One thing that has come up in general is how to deal with the basic Environment class definitions:

• Fully vs Partially Observable
• Deterministic vs Stochastic
• Discrete vs Continuous
• Benign vs Adversarial           

All those definitions tend to be fairly good black and white approximations but have little gray areas. Folks seem to be getting hung up in the gray.

For Instance: one homework question asks if coin flips are Partially Observable and if they are Stochastic or not. There seems to be some confusion about the scope of Observability, e.g., if you don't know the future is the system Fully Observable? Or from a different tack, "If you don't know how your Adversary is going to respond, is it Partially Observable or even Stochastic?"

Because I think that being Fully Observable covers just the current system state and doesn't preclude being uncertain about future states, in this context I would say: "Do we know the entire result after each action is performed, or is there still ambiguity in the current state of the system?"

There's also confusion about Discrete vs Continuous. The questions are more philosophical than practical, such as "Can one even have a Continuous representation of a system?" or "Since the result of a coin flip is dependent on exactly how it is flipped, isn't that Continuous?" I say, lighten up a bit...If you've got something that can take any real-number value, it's Continuous. But if it can only take a sub-set of values, it's Discrete. So the result of a coin flip is ??? -- maybe I'll answer next week, eh?

And there was a funny mis-apprehension on the Unit-1 quiz that asked if a robot car driving in a "real" environment was Adversarial. The given answer was No -- admittedly with a little joshing around. I think this is because the instructors live in Palo Alto and only have to deal with Volvo-Soccer-Mom's passive aggressive driving, rather than in New Mexico where every drunk wants to be in your lane.
</IMHO>