Monday, December 3, 2007

Item pricing rolls on...

My World of Warcraft item pricing database, which I've discussed previously, continues to grow in terms of features, visitors and data. One important new feature, and the most widely requested one, was a histogram that accompanies every graph. This histogram shows how many data points went into generating a given day's data and gives you a good sense of how reliable a price might be. This is especially important when looking at prices that are for a specific realm and faction, where the data might be very thin.

I've also added packaged reports on the most and least volatile items. Volatility is a metric used in the financial world to measure the standard deviation of a set of prices relative to their mean. This tells you how "stable" or "volatile" a price is at any given time in a way that can be compared across multiple stocks, bonds, currencies or (in my case) WoW items. If you look at the most volatile report right now, you'll find that it's dominated by items which have no inherent value and are priced arbitrarily by those putting them up to see if they can get some cash for them. On the other hand, stable items tend to be those which are crafted as the seller knows how much it cost to make the item and most sellers will want to make some profit on their items.

For the future, I'll be working on a conversion to a template library for the source code. This will make it easier to make other changes down the line. I'm also going to be adding new reports that look at how much items are changing in price over time and which items prices have gone up or down the most recently (probably on a week-over-week basis).