I’m going to describe here the algorithm we use in the widget to determine which locations to display. We are considering using this algorithm for the main site and we want our readers to comment on that and suggest improvements. It’s fairly simple.
First, we set a limit of 60 markers. If there are less than 60 markers in the span of view, all of them get displayed. If there are more than 60 markers, then we use our statistics to determine which are more important. Right now, we use “last viewed”. So markers that have been viewed recently go on the top of the list, and markers that haven’t been viewed for a long time go on the bottom of the list. Every time you view a marker, it goes to the top of the list.
I realize that this may not be the top choice statistic to use, but for right now, it’s the cheapest in terms of computing resources and development time. We can switch measures fairly easily, but we’re going to monitor how this one works out first.
Another aspect of this design: suppose you looking are on the neighborhood level. The neighborhood markers get displayed first. Then then street level markers. Therefore, if there are more than 60 neighborhood markers, no street levels will get displayed. If there are 40 neighborhood markers, all of those will get displayed, and the top 20 street level markers will show up. Likewise, city markers take precendence over both.
Play around with our widget (http://blog.stickymap.com/?p=87) and tell us what you think either by leaving a comment, or emailing us at admin@stickymap.com.
Max