Friday, June 27, 2008

The Wisdom of One

I've written a couple of blog posts on The Wisdom of the Crowd in the past, but The Economists notes a study about how asking a single person for different answers can yield better answers than asking just once. The results are better if the time between answers is longer. I'm not sure why this is all that surprising. The researchers, Edward Vul and Harold Pashler believe this phenomena may be that the brain is making hypothesis and then updating ones that are incorrect. This is probably true to some degree. But another possible reason may come from the field of machine learning.

Fundamentaly, the memory is simply a feature extracture and like all feature extraction techniques they can be quiet noisy. For example, it has been shown that doctoring images can make people remember events differently, even if they were at the event in question. In effect, by asking many people or asking the same person multiple times is taking a statistical sample, for which the mean is a better indicator on average (minimizes the square error loss). Another effect seen here is that better answers are gained by lengthing the time between questioning. This can be explained by Monte-Carlo Maximum Likelihood (MCML). One noted effect in MCML is that neighboring samples are correlated, but by taking samples spaced farther apart, the correlation decreases and closer to being independent and identically distributed.

I wonder if this could be an explanation considering something missing in the hypothesis by Vul and Pashler: what feedback was given to people to say their first answer was wrong? True, simply asking a question again probably makes the person question is correctness, but a control study group would be needed. One example is to tell people upfront that they will be given two guesses, but they will be rewarded inversely proportional to the combined answer. For example, if the correct answer in "guess a number I am thinking" is four, but one person bets four and nine, while the other person bets three and five, then the second person gets the reward.

Wednesday, June 18, 2008

Where's the RIAA on this one?

The earliest form of a computer playing music is discovered. One wonders when the RIAA will sue...

Tuesday, June 17, 2008

Dragons and psuedoscience

Brian Dunning has a must-see movie about critical thinking and the fallacy of pseudoscience. Also, on the subject are perpetual-motion and free energy machines that violate thermodynamics.

Wednesday, June 11, 2008

If you can't beat them, join them

In an attempt to be the EU of music, Merlin, tries to "to turn indie bands and labels into a loose, decentralized version of the major label." Recently, they are trying to prove their worth in a deal with online sites much like what major labels have. Of course there are two issues at play. The first is the continual instance of the major labels (and multimedia distributers in general) that everyone is out to get them and that they carry no fault. It amazes me how unaware the industry is about the fact that hits have fallen faster than the industry as a whole. The bottom line is that controlling the distribution channels ultimately chokes competition and ruins quality. Call me a skeptic, but I find it hard to believe the deal between MySpace and the major labels is anything but a plot to ration music on the internet. Are we headed for Radio 2.0?

The second issue is whether Merlin actually stays true to its message. As these major labels try ration music on the internet, will Merlin not be pulled by the appeal of control and power? Sure, there is a ton of revenue in The Long Tail, but it also involves a lot of work. What is the revenue generated from investment in a new band? As a band gets bigger, it's costs go up, but the rate of return is higher (and probably, more secure - when will U2 or Coldplay not sell out?). Also, you need fewer bands to make the equivalent revenue. Things are even more appealing if you can control the distribution channels. Will Merlin be able to pass this up and stay not-for-profit? Probably, but more likely, Merlin's Indie bands will jump ship if they start becoming a hit, ensuring Merlin will not eat up "too much" of the market.

So we are left with the status quo. A new distribution channel will open, independent bands will flock to it to get their message out, the record labels will sue, but eventually sign a deal which chokes competition, and repeat.

Tuesday, June 3, 2008

The Filter

I've been playing around with The Filter this morning, which is yet another recommender site. This one is a little different than Pandora or for two reasons. First, it recommends music, movies, and web-based videos. Second, it has a more involved enrollment stage. The approach starts by asking you what 3 genres you like out of a list of about 13. However, the genres are typical genre labels and I found myself unhappy with the selection. For starters, there is Rock/Pop as a single selection and no sub-genres under this category. Given my particular tastes, they might have well have asked, "Hey, do you like music?" Anyway, I picked three genres ("Rock/Pop", "Blues", and "Jazz"... oh did I mention that Classical is not even a choice?).

The next page gives me a list 3 "prototypical" artists for each of the three genres I picked. I will give The Filter credit, in that they allow the user to listen to a sample selection from each artist. They use a slider scale to pick a rating. There are a few problems with the choices because they are largely generic and do not encompass the range of each genre. For example, under the "Rock" category, I was given the bands "Green Day", "Blink 182", and "U2." I did this three times and got the same bands twice, so there is probably a short list. I hardly think this represents the Rock and Pop universe. For starters, Green Day and Blink 182 are both considered to be Punk bands, albeit at different times. U2 is so generic that I doubt that anyone truly hates them. They might as well have The Beatles or Led Zeppelin. The other genres were not better with choices like Ray Charles, B.B. King, and Miles Davis. There is a selection for "More artists," but you must change at least one of the sliders under the genre to get it to change. What if I don't know or are unfamiliar with the particular band? Further, what if I think that these choices are OK, but are not representative enough of my particular interests?

The movies section was the same thing: pick three genres and then a list of choices under these. I picked Action, Comedy, and Drama. For Drama I was given the 1940's version of "The Grapes of Wrath", "Casablanca", and "Mildred Place". I have heard of these, but I haven't seen them... these movies are well before my time. For action, there was John Woo's 1989 "The Killer" (I haven't heard of this before" and Goldfinger (again, who doesn't like James Bond?!?). For Comedy, I had the cartoon version of "The Grinch", "The Bank Dick" (never heard of this... a porno for rich people?), and "The Honeymooners [TV Series]", which is again, long before my time. I skipped this, since I'm not familiar enough and was more interested in music anyway.

When I finally got to the recommendations page, I was pissed. Most were bands that I would never listen to, much less buy their stuff... (e.g., Usher). The ones I had heard of where the exact ones they asked me to rate. "You like B.B. King, so you might like B.B. King." Ugh! Things got a little bit better after I incorporated my data in that the recommendations made more sense. However, one wonders why the enrollment phase is necessary. It's a time waster.

One very useful feature are the sliders. When you select a recommended track, there are two sliders. One is for the "familiarity" of the track so that users can select how much they would like to explore The Long Tail. Another is based on newness so a user can select if they only want music made recently or if they don't care.

The Filter also has an application to download that will interface with iTunes, Winamp, and Windows Media Player. I tried with iTunes and it crashed. I'm not sure if that was a problem related to iTunes, the Filter, or something else. I'll try again later with iTunes and see what happens. I tried it with Winamp and played a song. One thing I like is that you must play a specified length of the song (you decide) before it's supposed to scrobble the track. I played a single song and awaited my recommendations. However, there seems to be issues because it says that it can't because either the playing track was not recognized or there is not any related music in the library. However, when I went to the website, my recommendations where more or less what I would expect from any recommendation service. It would probably be good to have some sort of message saying "We are sending this information".

There was one major problem in that the application was supposed to scan my library and send that information to The Filter's servers so that they would not recommend music I already have. However, this appeared not to happen based on the recommendations I received. I reinstalled the application again, but this did not help things. I'll keep The Filter open for a couple days and report back if this gets fixed.

All in all, The Filter is probably a handy little tool, depending on how recommendations are done. The FAQ site says that it uses "Bayesian mathematics" and "artificial intelligence" to make the recommendations and that these are based on items bought or listened. However, I have no idea if these recommendations are given by collaborative filtering, similarity by tag data from (or something similar), or by data mining sites like (or some combination). The enrollment question phase should be skipped all together. Almost any user will have some music locally stored or have a profile at Second, it needs to made obvious to the user that data is being sent immediately when the application starts. Also, I wonder if it's possible to use the percentage of times that I've skipped or played a song in my iTunes profile? This would generate recommendations immediately instead of in a couple days after installation. Anyway, follow-up in a couple days.

Monday, June 2, 2008

A how to for myspace bands

Wired has a wiki page with a "how to" for promoting your band on myspace. I am a facebook guy, but still, pretty cool reference. Although, there are some rather obvious tips... like how attractive people are more photogenic.