Understanding Scopes in Google Analytics 4 (GA4)
Google Analytics 4 (GA4) revolutionizes data analysis with its event-driven model, departing from the structure of Universal Analytics (UA). At the heart of GA4’s functionality is the concept of „scope.” This defines the level at which data is collected, organized, and reported. To maximize GA4’s potential, understanding how scopes work is essential.
What is a Scope?
In GA4, a scope is the level at which data is grouped and analyzed. It determines how metrics and dimensions relate to one another, as well as the context in which data is processed. The three scopes in GA4 are in a following hierarchy:
User
Session
Event
Let’s explore each in detail.
User Scope
User-scoped dimensions shows you where the user came from during their first visit on the website. Those dimensions always have a prefix of „First user” + dimension name, e.g.: „First user source”.
You can find those dimensions in Reports – > Acquisition -> User Acquisition report
or in Reports -> Business objectives -> Leads – > User acquisition if your GA4 property is relatively new.
When user visits your website multiple times, his first user traffic source will always remain the same. This traffic source can’t be overwritten by other traffic source.
Let’s imagine this situation for a single user
- First session – Organic – January 1st – User saw few product pages
- Second session – Direct – January 3rd – User added an item to cart
- Third session- Paid Click – January 5th – User bought the item with transaction id=123
If you look at the key event: purchase with source in the first user scope, it will result in google / organic, because it was the first traffic source that brought the user to the website.
We can see, that for a selected date range, we’ve had a total of 24 conversions. First user traffic source of 17 of them was google / organic. This report has all the metrics for the selected date range, but it doesn’t mean, that the user’s first visit was in the selected date range. It could be prior to the purchase date, but the first user scope kept the traffic source.
To better understand how Google Analytics recognizes new users, please read this article
Session scope