Use session metrics to evaluate content paths

Sometimes considered "legacy metrics," session metrics, like bounce rate or exit rate—are helpful diagnostic tools for obtaining a deeper understanding of the performance of campaigns or content items. 

In Amplitude Analytics, you can find session metrics in the Data Tables charts, on the Metrics tab. Other than session totals, session metrics—bounce rate, exit rate, entry rate, entries, and exits—are not available as standalone metrics in Amplitude Analytics. Instead, these session metrics are calculated from the group-by you select, and will only include active events in the computation. Amplitude Analytics uses the group-by to determine how many values are present, and the sequence to be used for calculation. 

Feature availability

This feature is available to users on Growth and Enterprise plans only. See our pricing page for more details.

Select a good group-by property

The most common properties to select for your group-by are page- or screen-level properties that change as a user interacts with your app or site. These work well because they are likely to vary between most of the relevant events, and are set frequently enough to signal a bounce when needed.

Example: Group-bys and session metrics

Amplitude Analytics will use the number of values of your group-by property to determine whether to classify a session as a specific metric, such as bounce, entry, or exit.

Here are three example sessions:

Session 1

1. Event: Page View
Page = A
2. Event: Click
Name = 1A
   Type = Ad
3. Event: Page View
Page = B

Session 2

1. Event: Page View
Page = B
   Name = 1A
   Type = Ad

2. Event: Click
Name = 1B
   Type = Ad

Session 3

1. Event: Buy
Amt = $15
   Prod = 1

A Page View event is either a default event captured via the Browser SDK, specified via the settings in Amplitude’s Marketing Space, or defined in a Data Tables analysis as a bounce rate metric.

Bounce

A bounce is a session where only one Page View event is triggered; this is also known as a single-page session. 

Amplitude calculates the bounce rate as a percentage based on the following formula: 

1count of single-page sessions / the **total** number of sessions

Bounce rates with a group-by are calculated by:

1count of single-page sessions grouped by the first **non-null** property value /
2the total number of sessions grouped by the first **non-null** property value

To determine if the example sessions above are a bounce:

• Regardless of the group-by property, like Page or Name, Session 1 would not be counted as a bounce because it contains more than one Page View event.
• Session 2 only contains one Page View event. If you grouped by the Name event property, Amplitude Analytics will classify this session as a bounce. It would be grouped by the Name value of "1A" since it appears first in the session, and the bounce rate would be 1 / 2 (50 percent).
• Regardless of the group-by property, Session 3 would not be counted as a bounce because it does not contain any Page View events.

Entry and exit

Session Entries are defined by the first non-null value for the group by's property within the session. Session Exits are defined by the last non-null value for the group by's property within the session.

The entry and exit rates are then calculated as a percentage using the following formula:

1the number of entries or exits / the **total** number of sessions

Example, for the same sessions above:

• If you group by the Name event property, both the entry and exit rates will be grouped under "1A" because it's the first property value of Name. The entry rate would be 2 / 3 (66.66 percent) and the exit rate 1 / 3, or 33.33 percent.
• If you group by the Page event property, the entry and exit rates will be grouped by “B.” The entry rate would be 1 / 3, or roughly 33.33 percent. The exit rate would be 2 / 3 (66.66 percent).

Differences between session totals and PROPCOUNT(session IDs)

It's common to want to compare results of one Amplitude chart versus another, but not all chart analyses are interchangeable.

For example, you cannot compare the results of a session totals query in a Session Metrics chart versus the PROPCOUNT(session IDs) formula in the Event Segmentation chart.

These two analyses cannot be compared because of the following differences in their logic: