User scenarios which would benefit from streamable fonts

Hello, everyone!

In order to determine which strategy we should pursue for a streaming font interface, we should first determine which situations we are trying to improve. Once we have determined the specific scenarios that we are trying to attack, we can then create a benchmark to see how bad we are right now and to judge the various proposals.

The document <https://docs.google.com/document/d/1AQ2VwiVwF77H2h_nuDHR1A5hRyGlpyIQYpYodMtEz1w/edit> from Google sent a few days ago describes "Minimize latency for client to view webfont styled content.” I’m hoping we, as a group, can go further than this and describe:

1) Are we concerned with just first page load? Or are we concerned with interactions users make with pages? Are we concerned with “infinite scrolling” pages?

2) Which types of webpages have big problems? Is there any way to characterize the types of sites that should see an improvement?

3) Which types of fonts most need improvement in their loading experience? Fonts with many independent glyphs, like a Chinese font? Fonts with complex shaping rules? Fonts with complicated outlines?
    => The Google Fonts corpus could provide some big insights here. Which fonts are the ones that require big downloads but have much of the file unused by the browser? Can such fonts be characterized? In general, which fonts are the most popular?

4) Regarding comparison against the existing unicode-range solution, should we try to make a cost function that includes both breaks in shaping and latency? Or should we consider that a break in shaping should be forbidden? Should we try to incorporate how many text flashes occur during each user interaction?

Figuring out the answers to questions like these will help us better be able to weigh each possible solution. I’d love to hear everyone’s thoughts about these sorts of things.

Thanks,
Myles