On Fri, Oct 25, 2013 at 5:43 PM, Steven Walling <swalling@wikimedia.org> wrote:

On Fri, Oct 25, 2013 at 2:16 PM, Diederik van Liere <dvanliere@wikimedia.org> wrote:

One piece of feedback: combining threshold and 'time to threshold' seems to make things more confusing. For example, when you select sum as an output, you also get the sum of the time to threshold. That result -- like "time_to_threshold": 92.7864 -- seems to be simply the sum of hours for the members of the cohort. Knowing that it took the cohort a combined 92 hours to reach the threshold isn't very actionable.

So.......what are you proposing? separating it as two separate metrics?

Separating is probably the simplest thing to do, but you could also just remove Sum as an output for time to threshold. The two metrics can make sense together, if you check out a result like:
        "Average": {
            "threshold": 0.1735, 
            "time_to_threshold": 0.7863
        }

Hi, so there's a brief story behind this. Stefan caught this problem before we deployed and I made the call to push it out without fixing. In wikimetrics parlance, "threshold" and "time_to_threshold" are submetrics of the Threshold metric. I think the right solution here is to make a map from Aggregations to Submetrics. This would describe which aggregate is allowed for which submetric, and we could display this mapping along with an explanation on a page under /reports

The reason we chose to compute the metrics together is that if you think about it:

threshold = time_to_threshold is not null

So resource wise, you're basically getting it for free.