Is it fair to say that "sex positive" is equivalent to "sex friendly" ?

Hopefully I will be wrong about this, but I'm not expecting this to be very helpful. In dense areas of SF, where I live, open parking spaces last less than a minute - sometimes only a few seconds. If where you're parking isn't densely populated, then you don't need the app at all, because you can easily find a space.

This is a very helpful blog post from about a year ago. We implemented something similar to a Wilson score to power the default sorting for the millions of reviews we have at RateItAll. In general, with a system like this, the items with the most reviews are going to rise to the top. This might not be what you want. You can easily see this effect with something like our "Events of 2010" list: http://www.rateitall.com/t-2987869-events-of-2010.aspx

>items with the most reviews are going to rise to the top

Yes and no. Anything with a larger N is going to make for greater confidence in the rating. But that rating still depends on the number of positive and negative reviews. So if a product has a large number of ratings, but they are 50/50 positive and negative, then it's not going to rise to the top simply because it has the most reviews. The algorithm would presumably be very confident about placing it in the middle of the pack.

>So if a product has a large number of ratings, but they are 50/50 positive and negative, then it's not going to rise to the top simply because it has the most reviews.

What I'm saying is that it will rise to the top because even though only 50% of the ratings are positive, it will have many many more positive ratings than the nearest next item. That 2nd item may have a much higher percentage of positive ratings, but a much lower number of total ratings.

It seems to work as described in the article:

    require 'rubygems'
    require 'statistics2'

    def ci_lower_bound(pos, n, power)
        if n == 0
            return 0
        end
        z = Statistics2.pnormaldist(1-power/2)
        phat = 1.0*pos/n
        (phat + z*z/(2*n) - z * Math.sqrt((phat*(1-phat)+z*z/(4*n))/n))/(1+z*z/n)
    end

    puts ci_lower_bound(60, 100, 0.10)   # => 0.517809505446319
    puts ci_lower_bound(500, 1000, 0.10) # => 0.474027691168875
    puts ci_lower_bound(50, 100, 0.10)   # => 0.418847795168265

The top ranked result has 60 positives out of 100, and beats 500 out of 1000 - almost 10 times as many positive votes.

A couple of notes there: first the item at the top of the list has more than an order of magnitude more ratings than the rest. For most ordered lists, this is probably an edge case that may have to be dealt with separately.

Finally, I've got to say, 26 reviews (for the #2 item) doesn't seem insignificant, and the #2 item seems to have something like a 15% higher _average_ rating. Also, on another trending rating (http://www.rateitall.com/t-3239938-2010-ncaa-tournament-team...), the #2 has a significantly higher rating (17-18% it looks like), but only one less review: 4 vs. 3. I think if I were sorting either of these based on the average rating and the # of ratings, I would have done both differently.

Based on this, it seems that the Wilson score probably _over-emphasizes_ sample size, especially on things like ratings on high-traffic internet sites that may have orders of magnitude swings in the number of ratings.

It seems like the Amazon method of average works just fine, except for items with very few ratings possibly receiving disproportionately high ratings. Again, edge cases, which should probably just be penalized manually.

I agree. I've written to SJ twice and gotten follow up phone calls from the right people within Apple both times.

We decided to forego the merchant account and instead have been using Amazon Simple Payments with success. They've been excellent at closing transactions.

Enlightened self interest doesn't work on a scale necessary for a civilization to function.

Every nation that has next to no government and every man is free to do with his life as he wishes is a giant shithole that teeters in and out of revolution. Want to see objectivism at work? Go visit Somalia or the Democratic Republic of the Congo. In those countries every man is free to pursue "... his own happiness as the moral purpose of his life, with productive achievement as his noblest activity, and reason as his only absolute." Countries full of people who are "all noble heros free to pursue their dreams". Too bad their dreams all involve mass murder and slavery to pursue personal wealth and power.

Hobbes was smarter than Rand. We have a Government to protect us from each other.

I don't think you'll find Rand objecting to a government that protects its people from physical aggression or coercion. The problem I have with most world governments (including my own), is that they try to (and fail at) protecting people from matters that the people are capable of handling themselves. In doing so, they rob people of their motivation and self satisfaction.

I understand why people would think that Rand says "you should only care about your own life and happiness". But that is bullshit. It isn't considered bad to care about and care for other people (look at Dagny and Hank/John/Francisco). What Rand is railing against is being forced to care about another person (which is what the government does to the producers by threat of coercion).

I'm a firm believer in Rand's theories, but that certainly doesn't stop me from donating my time and money to worthy causes. The important part is that my donations are made of my own FREE WILL and not forced at the barrel of a gun.

Rand wasn't an anarchocapitalist.