Whenever you see a dotted line in an Amplitude chart, that means Amplitude is still receiving events for that day or data point. Once all relevant data has been collected, the dotted line will become a solid line.
For example, let's say a new user performed their first event on June 10 at 7pm. On June 12 at 11 am, you check the retention chart and see this:
The dotted line extending to the June 10 data point tells you there still may be outstanding events for that day. This happens because the Change Over Time metric is calculated in 24-hour-windows. And at 11 am on June 12, we are still within the user’s Day 1 retention period:
- Day 0 retention was from June 10 at 7 pm to June 11 at 7 pm
- Day 1 retention is from June 11 at 7 pm to June 12 at 7 pm
- Day 7 retention will be from June 16 at 7 pm to June 17 at 7 pm
As of 11am on June 12, this user's Day 1 is not over, which means this data point could still change.
We can see another example in this funnel chart showing conversion over time:
In this chart, why are all the data points linked with a dotted line?
Again, our user hasn’t been active long enough to meet the conditions of the chart. In this example, you want to see users who:
- Were new on June 1, and
- Performed both the first and return events (in this case, “Play Song or Video” and “Purchase Song or Video”) within 30 days of becoming a new user.
Because you are checking this chart on June 12, any new users from June 1 who have not yet performed both events still have time to do so. They haven’t been active for 30 days yet, so Amplitude recognizes the possibility that this data may change in the future.
On July 1, this dotted line will turn solid, because Amplitude will have collected all the relevant events by then.