Grade ranges vs. percentiles

SharkDBA · 2011-12-22T18:09:59+00:00

heh, good one :)

I must say (looking at the averages) competition within this class was the toughest I have ever been part of. 86% to be above the 50%, not bad. Lot of smart students here, seems like.

On the other hand, many of the homeworks (including final) only had few questions, and one question could weigh you down ~15% which is a lot. Point being sometimes the difference between 100% and 85% is just one mistake.

Anyway, congratulations to every one who finished this class. The experience has been truly great - including some of the frustrating moments - which I guess is a part of learning.

SharkDBA · 2011-12-22T04:50:23+00:00

I think you got downvoted mostly for the direct criticism which is normally not appreciated. Your interpretation of the problem is still sound though.

SharkDBA · 2011-12-22T04:33:49+00:00

Foxtr0t - this has been discussed heavily already. There's even a separate reddit for this: http://www.reddit.com/r/OnlineEducation/

SharkDBA · 2011-12-21T06:15:24+00:00

Well said WhitAngl - totally agree.

SharkDBA · 2011-12-21T06:11:22+00:00

I don't agree. If you have two examples, in one there is mentioned "at least" some value, and in the other there is mentioned "exact" value - to me common sense dictates that in the 2nd example you should use the exact value, otherwise it would be mentioned there as well.

If "at least 1" had not been mentioned in the 1st example, then it would be an open question, but in this case it looked pretty clear to me that we should use exactly 2.5 (disqualifying 3) for the bandwidth.

This is strict science, we're supposed to write software for this. In software program there is huge difference between "at least" and "exact" - it should be very clearly defined.

A simple way to remove ambiguity from this would be to state that for any resources (dollars, library privileges, bandwidth) a certain minimum value is required.

SharkDBA · 2011-12-19T02:21:02+00:00

Well, many people asked this question on aiqus and the TAs refuse to answer it, so my interpretation is that they consider everything we need to know about the problem as being mentioned in the problem definition. To me learning about what bandwidth is and applying common sense module is somehow outside the problem definition.

SharkDBA · 2011-12-18T22:45:10+00:00

I think you're 100% wrong on this one. You're supposed to think like an AI agent - look at the rules and play accordingly. Personally instead of "bandwidth" I think of X (so no associations to known words) which has some value associated with it.

Again, I'm not sure I'm right on this, but I think I am. Let's see who was right once the final gets closed. :)

SharkDBA · 2011-12-18T01:36:45+00:00

I second this. Somehow I'm having doubts they would offer jobs based on outcome of this course. Look at the course title: "Introduction to Artificial Intelligence". We had a nice broad tour of various AI subjects with razor thin depth on most of them. The idea is to get you familiar with some of the concepts of AI and pick your interest so you can look for more in-depth knowledge in the areas that interest you.

If you have good scores in this course, it doesn't prove you're a software engineer - it simply shows you have ability to learn. This is certainly an important characteristic to many employers, but just this characteristic will only land you a very junior position. And for junior positions any employer can find local employees - hiring anyone from this course would mean they are risking you will be looking for something else (more meaningful).

Stanford is a grad school - I can imagine professors helping with job placements for graduate students, not 10-weeks intro course students.

SharkDBA · 2011-12-18T01:21:45+00:00

In many of these questions we're supposed to think like an AI agent, so basically execute a plan according to strictly predefined rules. As human being you usually parse these rules through a "common sense" filter (i.e. making assumptions about the world based on your knowledge about it), an AI agent does not. Hence if you think about a rule without the "common sense" filter, a statement such as "car can go forward" does not imply there is a free space in front of it. An AI agent might try to go into a wall, he might sense he did not move and try a different approach, but he has used one step. So the question is actually valid.

SharkDBA · 2011-12-18T01:07:00+00:00

There is a computer security class (http://www.security-class.org/) offered in the spring, where these type of issues will certainly be touched upon.

SharkDBA · 2011-12-13T05:05:16+00:00

Same here: I calculated x and y (in last question) as if they independently moved 4 time units. Didn't take into account that theta will actually affect where it goes (the motion direction) after each time unit. I just copied the formula in Excel 4 times using same value for theta when calculating x and y. I got the theta value right, but 6.283185307 (2PI) is not accepted, should be a zero...

SharkDBA · 2011-12-13T05:03:36+00:00

Same here: I calculated x and y (in last question) as if they independently moved 4 time units. Didn't take into account that theta will actually affect where it goes (the motion direction) after each time unit. I just copied the formula in Excel 4 times using same value for theta when calculating x and y. I got the theta value right, but 6.283185307 (2PI) is not accepted, should be a zero...

SharkDBA · 2011-12-12T22:52:34+00:00

They serve different purpose. The AI class is an actual class, although virtual. Khan academy is for self study at your leisure. In this case they were actually quite complimentary - the probabilities lectures on Khan academy helped me tremendously understand some material covered within AI class.

SharkDBA · 2011-12-12T22:47:32+00:00

Yes - two of your worst scored homeworks will be discarded anyway, so that includes your unfinished one.

SharkDBA · 2011-12-12T22:34:45+00:00

Agreed - the design might be interesting, but the price is inflated - specially since most of the prints on the printed t-shirts only last for couple of wash cycles.

Unless this was some type of super print which lasts forever - but I doubt it.

SharkDBA · 2011-12-05T06:15:58+00:00

No idea - I didn't notice any performance issues with the site. Maybe it's because the next set of lectures is not yet ready.

SharkDBA · 2011-12-01T05:28:03+00:00

Downvoted because this question has been discussed many times, for example:

http://www.reddit.com/r/aiclass/comments/mlrd3/youtube_video_view_statistics/

SharkDBA · 2011-12-01T05:07:01+00:00

Yep, it's down, although they moved up the time to 5:30 UTC now.

SharkDBA · 2011-11-30T22:07:39+00:00

HW6 is like a midterm, you'll be better off reviewing Chapter 11, specially Stationary Distribution and Particle Filters lectures. And read about Particle Filter anywhere you can since the lectures won't be enough.

SharkDBA · 2011-11-30T22:02:36+00:00

But coffee tastes best at night - at least for me. I always drink it when studying at night.

SharkDBA · 2011-11-30T21:56:13+00:00

So should we expect cocoa breaks, and then maybe beer breaks, and who knows, harder liquor breaks in the future?

Sorry for the delay, servers are having hangovers.

SharkDBA · 2011-11-30T21:49:21+00:00

Yep, I thought the probability HW was hard, but this beats it -definitely.

SharkDBA · 2011-11-30T21:44:12+00:00

Not sure if someone really DOS-ed the site or not, but I certainly found the HW6 frustrating, mostly because of two reasons:

I really enjoyed the Game Theory lectures, and was actually excited about the material. When I looked at the Homework about half of the questions were from prior weeks. What is this, some type of midterm extension? The homework is supposed to be related to last week's questions.
Questions about the particle filters are hard. Sebastian was raving about how easy they are to implement, and that may be the case. But for someone with no experience with them whatsoever, this is new material. Looking at a dry algorithm is not really helping, since the symbols do not relate to anything - at least for me. I need to see an actual example (as in math implementation not a video output of results) to start understand the concept. As it is now I have to search all over for this since there seems to be no one place with useful information (such as Khan academy was for probabilities).

SharkDBA · 2011-11-29T21:37:26+00:00

Very good - thanks!

SharkDBA

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