Archive for September, 2008

CNN and the Debates: ‘Audience Reaction’

Friday, September 26th, 2008
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Anyone have any idea how the little scrolling “Audience Reaction” is measured? CNN has one trendline for independents, republicans, and democrats, and I’m not sure where they’re getting those numbers.

Update 1: Dennis left a comment with this CNN link which gives a partial answer: “Voters watch the debate from Columbus, Ohio, and give their reaction to the responses in real-time.” But how this is done is not clear; nor is it stated how they gauge who is republican, democratic, or independent (presumably self-identification).

Update 2: Ernanio points out “They have a bunch of potential voters from OHIO seated in a room with a dial thingamaging on their hands that when rotated can go from 0 – 100 to show how much they are liking the candidates intervention.”

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Posted in MyChances.net | 153 Comments »

Update: Probabilities now mean something

Thursday, September 25th, 2008
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Yesterday I updated the algorithm that spits out the probability (your chances of admission) for each person at each school. These new probabilities should be substantially more predictive than the old ones. (This change will not move <50% predictions above 50%, or vice versa. What has changed is only the scale; some rankings that were previously 56% might now be 75%, wholly dependent on which school we’re talking about.)

Previously, I had incorrectly converted between odds and probability. Now, I have changed the algorithm to correctly convert between the two. (Why this matters is idiosyncratic to how we process the data; suffice it to say that this matters.) In looking over the numbers at a couple of schools, this seems to have substantially increased the reliability of the predictions. It’s still not perfect, but it’s better.

To learn more about this, you can read some posts by ‘badass’ about this previous problem. 

As ‘badass’ noted, a good model should, more or less, work like this:
Say that there are 25 people who each have a 20% chance of getting in. If the model isn’t great, then maybe 15 of those (60%) will get in, or maybe 1 of those (4%) will get in. If the model is great, then 1 in 5 (20%), or about 5 of those people, should get in. The models aren’t perfect, so this won’t be exactly the case, but now we’re much closer to that at many colleges. 

(As an aside, you can see how a ‘perfect’ model will necessarily get predictions ‘wrong’. A perfect model that gives 10 people a 60% chance should be “wrong” on 4 of them: 4 of them should not get in. One that gives 10 people a 90% chance should be “wrong” on 1 of them. For the model-maker, these are the desired results.)

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Posted in MyChances.net, Status Update | 3 Comments »

First look at Google Chrome

Tuesday, September 2nd, 2008
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In case you haven’t heard, Google Chrome is Google’s latest open-source offering: a standards-compliant browser. The reason I’m interested in it is that it runs each tab as its own process. If I’m browsing two sites and one causes a crash, the other one doesn’t go down, as well. It also helps with memory management, theoretically keeping the overall memory use more appropriate after a long session of internet use.The reason Google is interested in developing Chrome is that it wants more control over how its Apps (especially Google Docs/Spreadsheets/etc.) are presented. If a silly flash arcade site crashes your browser while you’re taking a break from writing the next great novel in Google Docs, you’ll be rightly frustrated. The one-process-per-tab approach ensures that this won’t happen, paving the way for Google Docs to attain higher acceptance.Things that currently annoy me about Google Chrome:

  •  Quicksearch. I can’t right click in a field and make it a quicksearch option. In Firefox, I can right click in, say, the PHP search field and save that to a keyword, such as “php”. Then, if I want to search for the PHP function ‘asort’, I just type “php asort” in the address bar and it will take me right there. I can’t (yet) do this in Chrome.
  • Scrolling. In Firefox, my mouse is properly detected, allowing me to scroll slowly and smoothly, or quickly, depending on how I accelerate the mouse. In Chrome, the scrolling is overly “sensitive”, causing my scrolling to move much too quickly.
  • Tabs. When I middle-click on a link for the first time, it opens in a new tab. But when I middle click again on a link, it opens in the same tab that was just opened by my first middle click. Firefox gets this right by default: each new middle click opens up a new tab.

That’s it for now. More to come later.

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Posted in Uncategorized | 3 Comments »