Today: working on the Add New Experiment screen.

Some things still missing here: some UI for determining how long the experiment should run for. Unfortunately, this is best determined using the metric’s variance (the spread of its values across all the visitors), which 90% of the time the user will not know ahead of time. “Just run until I confidently detect any X% difference” is probably the way to go.

It’s been taking more time than I expected but I’ve been trying to do things “the right way,” including implementing an API to register custom variant and metric types. The first custom metric type is the the simple “conversion” metric.

Once this API is all set, I can then do fun things like implement my first custom variant type: variants set up using a simple [ab] shortcode. Ultimately, this API could be used to implement other variant and metric types like “time on page,” “comment submitted,” or even as specific as “WP e-Commerce checkout total.”