Summary

Unit count metrics with the daily participation rate rollup type measure the fraction of days that the user participated in an action during the experiment.

Use Cases

This metric type is an analogue for DAU, and is useful for growth accounting and for measuring upkeep of usage and retention.

Calculation

At the unit level, unit count metrics create a 1/0 flag for if they participated on a given day.

At the group level, the mean is calculated as the SUM of the unit-level flags divided by each unit's days in th experiment, divided by the count of UNIQUE UNITS exposed to the experiment.

This would look like the SQL below:

-- Unit Level
SELECT distinct
  unit_id,
  group_id
  COUNT(distinct date) as value
FROM source_data
GROUP BY
  unit_id,
  group_id;

-- Experiment
SELECT
  group_id,
  unit_id,
  date_diff(first_exposure_ds, today()) + 1 AS days_exposed
FROM exposure_data
GROUP BY group_id;

-- Group Level
SELECT
  group_id,
  SUM(value/days_exposed)/COUNT(distinct unit_id) as mean
FROM unit_data
JOIN group_data
USING (group_id, unit_id)
GROUP BY group_id;

Options

• Metric Breakdowns
  • You can configure Metadata Columns to group results by, getting easy access to dimensional views in pulse results
• Multi Source
  • Sums can be built with inputs from multiple metric sources; think of this as a UNION in SQL. This can be useful if you have the same measure in sharded or disparate tables
• Rollup Mode
  • Rollup Mode controls the specific way that Unit Count metrics are aggregated