Registration logic
When a visitor doesn't enter a registration ID for a session, Digital Analytics uses logic to map the cookie to the most likely registration ID. When a cookie is associated with multiple registration IDs (for example, when spouses share a computer but have separate registration IDs), the code gives greater weight to the registration ID entered closest in time to the session in question.
Logic for time
If the value for a registration field changes over time, Digital Analytics uses the value that was current during the time period shown in the report. For example, suppose a visitor says in January that he has one child and the same visitor says in February that he has two children. If you run a report in April on January data, that visitor would be grouped with the one-child visitors. If you run a report in April on February data (or on any month after February), the visitor would be grouped with the two-children visitors.
Different logic than IBM® Digital Analytics
The registration logic in Digital Analytics Explore differs from the logic in Digital Analytics. In Digital Analytics, a cookie is mapped to all associated registration IDs (rather than guessing which one is most appropriate). As a result, in Digital Analytics it is possible for a visitor to be considered both male and female if two people share a computer but have separate registration IDs. Further, when a value changes over time, Digital Analytics replaces the old value with the new. If a visitor has one child in January and two children in February and you run a report in Digital Analytics in April on January data, the visitor will be grouped with the two-children visitors.