There are scenarios when you're building an audience where the data type of an event or user attribute will not match the type you need to build your audience, e.g., an attribute is a string and you require a boolean or number match. In these scenarios, mParticle's audience builder allows you to change the data type of an attribute.
When creating or modifying Audience membership criteria and associated attributes, use the following steps to change the data type of an attribute.
1. Navigate to the attribute of interest and click on the current data type icon (highlighted in blue). 
2. Click on the data type of the attribute you need for your Audience definition.
3. Continue to define your Audience per the documentation here: Audience Documentation