In the digital context, Cohort Analysis is defined as technique to break your users into segments of groups for assessment who share similar traits, behavioral patterns or characteristics, rather than evaluating them as a single unit. This is a subset of behavioral analytics that takes data from a specific platform, application or a program and splits them into smaller groups or ‘cohorts’.
Cohort analysis is an effective tool to measure user engagement during a specific period of time. The cohort groups can be further divided into two types:
Acquisition Cohorts – this divides mobile app users by when they first signed up for your app. This could be the groups or cohorts based on the day, week or month when your users first installed or launched your mobile app.
Behavioral Cohorts – this divides mobile app users by the behaviors or actions that they might have or have not taken within an app during specific period of time. These actions could vary from app install, app launch, in-app purchases, form filling, transactions, etc. This could also be a combination of more than one of these discrete actions.
In the context of mobile apps, the average session duration is the time or length of an app session, averaged across all app sessions during a specific time period. Google Analytics calculates the average session duration by dividing the total length of all app sessions, by the total number of app sessions during a similar period of time.
For example, user A spent 200 seconds in your app, user B spent 40 seconds and user C spent 150 seconds in a day. The average session duration would be 200+40+150 divided by 3, which is 130.