Regardless of whether PageRank is "bad math" (the author being the arbiter of what's bad), it was never about being formally anal, it was about solving a problem -- making search much, much better than the then-competition.
PageRank solves the problem with flying colors. There is nothing wrong about having hidden constants that you tweak until you get the results you want. The alternative would be to, instead of coding what has become Google, attempt to find a more general solution. Maybe you'll find it. Maybe. And if you do, by the time you have, someone else will have come and made Google instead of you. And for what? Mathematical purity? Phobia of constants?
I suppose the author also feels much of physics is also bad, since it's riddled with constants upon constants, all of which are "ticking time bombs": http://en.wikipedia.org/wiki/Physical_constant
You, and many others, seem to imply that being "bad math" (mathematically not sound) is the same as being "bad" (in the broad sense). The author never said that the method was useless, nor anything similar. PageRank was an obviously great advance at the time, but this does not mean that it can not be improved.
Now, if you accept that it can be improved, the author has a great point: trying to understand the role that this made up constant plays in the algorithm (and getting rid of it if possible) is a clear path to what might be an improvement.
Oh, and "physical constants" are not even remotely similar to using a made-up constant. Physical constants are measured experimentally, meaning that they "exist" in the object that the mathematical model tries to explain. Now tell me how do you measure ".85" being an "existing" constant in the "ranking of website importance" object that pagerank tries to model...
> You, and many others, seem to imply that being "bad math" (mathematically not sound) is the same as being "bad" (in the broad sense). The author never said that the method was useless, nor anything similar. PageRank was an obviously great advance at the time, but this does not mean that it can not be improved.
I did not say the author said PageRank was bad. I merely said that it being "bad math" was irrelevant to the real world.
> Oh, and "physical constants" are not even remotely similar to using a made-up constant. Physical constants are measured experimentally, meaning that they "exist" in the object that the mathematical model tries to explain. Now tell me how do you measure ".85" being an "existing" constant in the "ranking of website importance" object that pagerank tries to model...
I was just showing how flawed his π analogy (he was comparing π to PageRank constants), and his reasoning how π is a time-bomb are.
You miss the point. The damping factor is arbitrary. Changing the damping factor changes the results of PageRank. So Google's search results are, in a sense, arbitrary. When Google controls the fate of so many Internet companies (by determining if they get traffic) having their search results be determined by an arbitrary parameter is galling. At least when Google blacklists certain domains you get the sense it is a conscious decision as one that can appealed against.
Google was successful then with PageRank, but maybe now they need something better? It is my personal opinion but building something as huge (now) as Google search on such a shaky foundation as PageRank is dangerous.
I don’t think physical constants are made up and they certainly aren’t hidden.
PageRank is one of more than 200 metrics Google uses in its search engine. Your presumption that it is the foundation, or even the most important metric, is unwarranted.
Well, generally how search works now was actually one of the first things I learned when I started working for Google, but my point was that you don't know and are just making things up.
Ok maybe you do know. However, it's odd that you bring up that you work at Google and then add nothing new to the discussion (everybody knows about the 200 metrics). How about: "You're wrong, PageRank has never been the foundation of Google search"?
I never said PageRank has never been the foundation of Google search or that PageRank isn't a part of search, just that there are other parts that you are not taking into account.
As to why I'm not saying exactly how Google search works -- I'm obviously under confidentiality agreements to not disclose that information.
It's not that physical constants are made up or hidden, it's that we know most of them with very limited precision, because they are determined via experiment.
Comments
Regardless of whether PageRank is "bad math" (the author being the arbiter of what's bad), it was never about being formally anal, it was about solving a problem -- making search much, much better than the then-competition.
PageRank solves the problem with flying colors. There is nothing wrong about having hidden constants that you tweak until you get the results you want. The alternative would be to, instead of coding what has become Google, attempt to find a more general solution. Maybe you'll find it. Maybe. And if you do, by the time you have, someone else will have come and made Google instead of you. And for what? Mathematical purity? Phobia of constants?
I suppose the author also feels much of physics is also bad, since it's riddled with constants upon constants, all of which are "ticking time bombs": http://en.wikipedia.org/wiki/Physical_constant
You, and many others, seem to imply that being "bad math" (mathematically not sound) is the same as being "bad" (in the broad sense). The author never said that the method was useless, nor anything similar. PageRank was an obviously great advance at the time, but this does not mean that it can not be improved.
Now, if you accept that it can be improved, the author has a great point: trying to understand the role that this made up constant plays in the algorithm (and getting rid of it if possible) is a clear path to what might be an improvement.
Oh, and "physical constants" are not even remotely similar to using a made-up constant. Physical constants are measured experimentally, meaning that they "exist" in the object that the mathematical model tries to explain. Now tell me how do you measure ".85" being an "existing" constant in the "ranking of website importance" object that pagerank tries to model...
> You, and many others, seem to imply that being "bad math" (mathematically not sound) is the same as being "bad" (in the broad sense). The author never said that the method was useless, nor anything similar. PageRank was an obviously great advance at the time, but this does not mean that it can not be improved.
I did not say the author said PageRank was bad. I merely said that it being "bad math" was irrelevant to the real world.
> Oh, and "physical constants" are not even remotely similar to using a made-up constant. Physical constants are measured experimentally, meaning that they "exist" in the object that the mathematical model tries to explain. Now tell me how do you measure ".85" being an "existing" constant in the "ranking of website importance" object that pagerank tries to model...
I was just showing how flawed his π analogy (he was comparing π to PageRank constants), and his reasoning how π is a time-bomb are.
You miss the point. The damping factor is arbitrary. Changing the damping factor changes the results of PageRank. So Google's search results are, in a sense, arbitrary. When Google controls the fate of so many Internet companies (by determining if they get traffic) having their search results be determined by an arbitrary parameter is galling. At least when Google blacklists certain domains you get the sense it is a conscious decision as one that can appealed against.
Google was successful then with PageRank, but maybe now they need something better? It is my personal opinion but building something as huge (now) as Google search on such a shaky foundation as PageRank is dangerous.
I don’t think physical constants are made up and they certainly aren’t hidden.
PageRank is one of more than 200 metrics Google uses in its search engine. Your presumption that it is the foundation, or even the most important metric, is unwarranted.
Initially it was the foundation and currently let’s just admit that neither of us knows.
Well, generally how search works now was actually one of the first things I learned when I started working for Google, but my point was that you don't know and are just making things up.
Ok maybe you do know. However, it's odd that you bring up that you work at Google and then add nothing new to the discussion (everybody knows about the 200 metrics). How about: "You're wrong, PageRank has never been the foundation of Google search"?
I never said PageRank has never been the foundation of Google search or that PageRank isn't a part of search, just that there are other parts that you are not taking into account.
As to why I'm not saying exactly how Google search works -- I'm obviously under confidentiality agreements to not disclose that information.
It's not that physical constants are made up or hidden, it's that we know most of them with very limited precision, because they are determined via experiment.