Product Analytics/Event logging

Identifiers

 * Types of identifiers
 * (string)
 * Identifies a client across multiple sessions. This is the "app install ID" on mobile apps and enables calculation of retention metrics for anonymous users since we do not have a user ID for those. MediaWiki-based instrumentation does not include this identifier in the events it sends.


 * (string)
 * Identifies a session. On the web, a session last for the lifetime of the browser process. Refer to T223931 for additional information. On mobile apps, where the app is allowed to enter a background state, sessions expire after 15 minutes of inactivity. If the app returns to the foreground after 15 minutes, a new session ID is generated.


 * (string)
 * Identifies a page view, applicable only on the web. Interactions with multiple features (instrumented separately) on the same page may be linked together via this identifier.


 * (string)
 * Identifies a sequence of actions in the same context or funnel. In the past, teams have used terms like "session ID" and "sub-session ID" to refer to a set of connected events, such as interacting with a widget. This identifier is useful for grouping together impressions with corresponding clicks, and for grouping together steps in a process such as making an edit.


 * (integer)
 * Starting at 1, this is a counter for reconstructing the order of events in the same activity. For a variety of reasons we cannot trust the timestamp of receipt or the client-side timestamp of when the event was generated for putting events in order. In cases where the exact sequence of events needs to be established, this identifier can be used to record which event happened 1st, which happened 2nd, and so on.

User
Information about the user associated with the event is contained in the  field.


 * Information about the user triggering the event
 * (boolean)
 * Whether user is logged-in (false) or anonymous (true)


 * (integer)
 * User's MW user ID; 0 if user is anonymous. User ID is specific the wiki that the event came from.


 * (string)
 * Cross-wiki username


 * (integer)
 * The total number of edits by the user at the time of the event. Growth team retrieves this with  to record it for their experiments. May be useful as a proxy for experience at the time of the event.

Page
Information about the page associated with the event is contained in the  field.


 * Information about the page the event was triggered on
 * (integer)
 * Page's numeric ID in MediaWiki


 * (integer)
 * Page's namespace code in MediaWiki (e.g. 0 for Main/Article, -1 for Special)


 * (string)
 * Page's title


 * (boolean)
 * Whether the page is a redirect or not at the time of the event

User Interface
Information about the UI associated with the event is contained in the  field.


 * Information about the interface the user saw when the event was triggered
 * (string)
 * Skin name (e.g. "Vector", "MinervaNeue", "Modern"); only applicable on MediaWiki, not mobile apps


 * (string)
 * "Light", "Sepia", "Dark", "Black"; currently only applicable on mobile apps, but Web is experimenting with it for MediaWiki


 * (object)
 * Information about the screen, such as dimensions


 * (integer)
 * Width of the screen in pixels


 * (integer)
 * Height of the screen in pixels