Difference Between using Contact Data vs Event Data for same DE

Question

Need to understand the difference in results If I use Event Data vs using Contact Data for the same Data Extension in a Source Entry Event or in a Decision Split.

Example

I have a DE named Alert where-in I am using this condition for Source Entry or Decision Split

AlertCategory Equal INQUIRY OR AlertCategory Equal NEW_ACCOUNT 
OR AlertCategory Equal NEW_ADDRESS

For making this condition, I use

Event Data -> AlertCategory for INQUIRY and NEW_ACCOUNT 

But for NEW_ADDRESS I use,

Contact Data -> ALert DE -> AlertCategory.

Note that in both the above Cases, the Data Extension is the same one.

Does it make any difference in results when:

1. Used for Entry Source Condition

2. Used for Decision Split.

Answer 1

You can find the difference between Event data and contact data in the below link:

https://help.marketingcloud.com/en/documentation/journey_builder/using_event_data/

In a nutshell, in the entry source condition, event data and contact data will not make much a difference unless your data extension is updated frequently

In Decision split, you need to use event data if you want to compare the attributes as they were in when they registered a journey and Contact data if you want to compare the attributes as the evaluation is done.

For e.g. if you are on a registration journey and sending mails only if registration flag (that is updated from external system) is false, then you need to use contact data as it would compare the latest status of registration.