... after getting enough users from directing all windows searches to their engine, they will create "search extensions" for all the sites hosted in a Microsoft server, and "special html/jsp search tags" for sites developed using their tools, which will produce a better placement on their search results.
Economics classes are good, but you have to go beyond economics 101 to see the whole picture. The officially accepted economic theory by the US government advisors is Keynesian-Monetarist, but these theories have already proven that they don't work. Keynes believed that during depressions the government could fix the economy by spending on useless projects, monetarists (Milton Friedman et al) believe that by controlling the supply of money with a fiat currency you can steer the economy out of inflation. The practical implementation of these incorrect theories has created a new phenomenon, stagflation, which is stagnation and inflation together. Other equally important theories that are not usually taught in the classroom are the Austrian School(Ludwig von Mises, F. A. Hayek) and the Supply Side School(Arthur Laffer). Several proponents for these theories have received Nobel prizes as well as the monetarists and the keynesians, so they are not exactly fringe wacko theories. They are just unpopular among government regulators, the economists they employ, and the academic programs they give funds to, because their conclusion is usually that the government should leave the economy alone. Both of these theories hold that the government should peg the currency to gold, or to some relatively fixed in supply and hard to manufacture comodity, so that economic agents can make long range plans using an objective measure of value instead of the subjective whims of whoever happens to be dictating economic policy at the time. In my opinion the Austrian school is the most correct of all, but the supply siders also have some interesting to say. You can read Ludwig Von Mises magnus opus, Human Action, online for free at the site dedicated to his memory: http://www.mises.org/humanaction.asp
All bayesian techniques are based in this formula: P(A|B)=P(B|A)*P(A)/(P(B|A)*P(A)+P(B|~A)* P(~A)) In the specific case you mention, the probability that a message is spam given that it comes from yahoo without taking into account any other information would be:
so, the formula takes into account not only what percentage of your spam messages come from yahoo, but also what percentage of your non-spam messages come from yahoo. So if 99% of your spam messags come from yahoo, but also 99% of the messages from your friends come from yahoo, the fact that a message is from yahoo does not change the prior probability that the message is spam.
Slashdot Mirror
I live in Denver, I was getting all psyched up to go, but too bad, it happenned already :-(
... after getting enough users from directing all windows searches to their engine, they will create "search extensions" for all the sites hosted in a Microsoft server, and "special html/jsp search tags" for sites developed using their tools, which will produce a better placement on their search results.
Ohh, I am salivating already! Thanks for the reference!!!
Economics classes are good, but you have to go beyond economics 101 to see the whole picture. The officially accepted economic theory by the US government advisors is Keynesian-Monetarist, but these theories have already proven that they don't work. Keynes believed that during depressions the government could fix the economy by spending on useless projects, monetarists (Milton Friedman et al) believe that by controlling the supply of money with a fiat currency you can steer the economy out of inflation. The practical implementation of these incorrect theories has created a new phenomenon, stagflation, which is stagnation and inflation together. Other equally important theories that are not usually taught in the classroom are the Austrian School(Ludwig von Mises, F. A. Hayek) and the Supply Side School(Arthur Laffer). Several proponents for these theories have received Nobel prizes as well as the monetarists and the keynesians, so they are not exactly fringe wacko theories. They are just unpopular among government regulators, the economists they employ, and the academic programs they give funds to, because their conclusion is usually that the government should leave the economy alone. Both of these theories hold that the government should peg the currency to gold, or to some relatively fixed in supply and hard to manufacture comodity, so that economic agents can make long range plans using an objective measure of value instead of the subjective whims of whoever happens to be dictating economic policy at the time. In my opinion the Austrian school is the most correct of all, but the supply siders also have some interesting to say. You can read Ludwig Von Mises magnus opus, Human Action, online for free at the site dedicated to his memory: http://www.mises.org/humanaction.asp
All bayesian techniques are based in this formula:* P(~A))
_ __________________
P(A|B)=P(B|A)*P(A)/(P(B|A)*P(A)+P(B|~A)
In the specific case you mention, the probability that a message is spam given that it comes from yahoo without taking into account any other information would be:
P(Spam|yahoo) =
P(yahoo|spam)*P(spam)
__________________________
(P(yahoo|spam)*P(spam)+P(yahoo|~spam)*P(~spam))
so, the formula takes into account not only what percentage of your spam messages come from yahoo, but also what percentage of your non-spam messages come from yahoo. So if 99% of your spam messags come from yahoo, but also 99% of the messages from your friends come from yahoo, the fact that a message is from yahoo does not change the prior probability that the message is spam.