As specified by Google, on December 1st 2022, the following breaking changes will occur:

1. Item-scoped dimensions like itemName are becoming incompatible with event-scoped metrics like eventCount. Item-scoped dimensions will still be compatible with item-scoped metrics like itemRevenue, user-based metrics like activeUsers, and session-based metrics like sessions.
2. Attribution dimensions like source are becoming incompatible with some event-scoped metrics like eventCount. Attribution dimensions will still be compatible with attributable metrics like conversions, user-based metrics like activeUsers, and session-based metrics like sessions.
3. Dimensions that include the query string like pagePathPlusQueryString will only be compatible with a limited set of dimensions & metrics.

What Does This Update Mean?

One of the benefits of GA4 is the option to configure a data driven attribution model even in its free version, and the chance to analyze the impact of each channel according to the acquisition or conversion funnel phase.

Meaning in GA4 we find news dimensions and metrics such as “first user touch”, which is focused on only new user acquisitions, and “session-driven” which is aimed at traffic acquisition reports and analysis;

On the one hand, these new dimensions help us define and analyze, in detail, the performance of each channel in a specific funnel step. On the other hand, they could be a bit “tricky” due to their scope and compatibilities;

When you have to build a report and get your insights, it is crucial to consider and understand how GA4 classifies those dimensions and to know which dimensions and metrics we can/should apply in the same report.

For example, if we talk about source and medium in GA4, we will find the following dimensions:

• First user source / medium
• Session source / medium
• source / medium

Which one should we choose? Which metric can we apply?

In order to answer both questions we need to follow the compatibility framework of dimensions and metrics.

As commented on at the beginning of this article, that schema is going to change starting from 1 December, and will have an impact on the default reports and custom reports of GA4 UI.

Some changes worth highlighting:

• Item-scoped dimensions will be incompatible with event-scope metrics.
• Attribution dimensions will be incompatible with some event-scope metrics.

This means that dimensions such as item name, item id, item category, source, medium and campaign name will be incompatible with metrics such as event count, add to cart, ecommerce purchase.

What will happen to your report?

The default report of GA4 UI, will be updated automatically but the custom report or the ones you have created in the Explore section, require a manual update by applying only compatible dimensions and metrics. This new approach implies re-training for all the GA4 users (at any level) in order to read, report, and analyze data in an accurate and proper way.

If you have any questions, or if you would like to know more about the GA4 upgrade and how it will impact your reports, please don’t hesitate to contact us.