Projects vary in the level of visibility or scrutiny they entertain. What are some of the causes of such variation?

Projects vary in the level of visibility or scrutiny they entertain. What are some of the causes of such variation? 
Do you think projects in your track have such variability? If so, how do you think a project manager can address this? If not, please explain why?
In what ways do you think that setting expectations when non-experts are involved is a problem, and how do you think a project manager can address this?
In what ways do you think that scoping projects that are cutting edge or don’t have a lot of precedents is a problem, and how do you think a project manager can address this?
What do you think are the special problems for project initiation for projects in your track? In answering this question, you might reference some of the challenges identified in earlier questions and/or identify some additional ones. Be sure to explain why these are special problems for your track (that is, they aren’t experienced in the majority of other types of projects). If you include problems that you have not already discussed, please also describe how a project manager can address them.