When should you use Notification Initiated Sessions (NIS) and User Initiated Sessions (UIS)?
First, let's review what the two types are:
NIS: Users are prompted by a notification to answer a question. (Signal- or Interval- Contingent). To learn more about NIS, click here.
UIS: Users choose to respond to questions on their own time. (Event-Contingent). To learn more about UIS, click here.
Using each of these types of sessions depends on the purpose of the study. For example, when gathering information on a construct that changes throughout the day (such as mood), using NIS will provide sampling over time.
However, when trying to learn more about certain things that happen intermittently throughout the day (such as smoking a cigarette), you might want to use a session where the person reports their behavior.
The two types of questions are often used in conjunction with each other. The combination of both NIS and UIS can provide a more complete look at an individual's experience and everyday life.
If you have any more questions, read this.