Hi Danielle,
In reference to your responses to Part 1, I agree with you that there is added benefit to assessing perceived risk and vulnerability separately. I found myself wondering about the perceived vulnerability construct, however. Even with the in-depth interviews, the reliability increased to just .74, which is not terrible, but definitely has room for improvement. I wonder whether the construct itself is a bit poorly or loosely defined. Based on the definition you provided from the authors, I am stretching myself to think about how one could feel vulnerable without engaging in risk behaviors... I encountered a similar type of "problem" in my dissertation work, where I tried to measure perceived vulnerability (to mental health problems). This was based on the health belief model, and I, too, had difficulty nailing down an operational definition that made sense and could be measured well. Again, there is room for improvement in both conceptualizing and measuring this construct! I agree with you that without a good measure, there could be misdirected research and policy efforts..
Jin