New oTree beta: better dropout detection in GBAT

[Chris @ oTree]

Hi all,

I have heard reports that while waiting on a group_by_arrival_time page, some participants get distracted and switch to another browser tab or other program/app. Then when the group finally is ready, they don't notice it, so they end up holding back the group.

I have implemented a change, where oTree detects whether the browser tab is currently focused (active) or not. If it is unfocused for a certain number of seconds (somewhere around half a minute, but could be more or less), they are considered dropouts, and excluded from grouping.

You can install this beta version with:

pip3 install -U otree --pre

By the way, I also added a snippet called "audio alert". If you put this code in your page, it will speak some words like "game is ready" so the user hears it and switches back to the game when it's ready: https://otree-snippets.herokuapp.com/demo

Let me know what you think!

Best,

Chris