I have called the approach I prefer to use for project management an "evidence based" approach (I have tagged it as EBPM on this blog). So it behoves me to define this in some way.

I am not saying that project managers per se do not use evidence to understand their project. I just don't believe there are comprehensive approaches to that evidence base and I believe there is waaaay to much emphasis on the governance side of things, but that is for another blog.

In many programs I have seen project managers report the status of their project by completing a form perhaps within a database or as a standalone document. This is done on a periodic basis perhaps monthly or even weekly at times. The project manager is ostensibly writing a short story about the project - where it is at, where it is going, what the problems and risks are and so on.

This form is then placed with all the other project reporting forms and consolidated, perhaps even printed, into a volume of project reporting of some sort.

These same project managers, before they fill out their form, seek input from the project team on how things are going in their area of responsibility. Sometimes these team members are remotely located or are even part of an outsourced team elsewhere. They provide a similar response by perhaps completing more forms or maybe they chat to the project manager about their sub-project or area of responsibility. And this might go on down the line as well. The sum total of progress for the project is based upon a series of what might be called small stories. 

So if you were a program manager, often what you are getting from your project managers is possibly mostly hearsay. When you report to the CEO, you are giving him/her hearsay as well. Often, it isn't evidence. 

Looking at this from a different perspective, let's look at primary and secondary academic sources. Primary sources come from the "horse's mouth" so to speak. These sources are people that observed the event. They were there at the time. Secondary sources are from an analysis of say primary sources. Sometimes a project manager can be a primary source and at other times, they are a secondary source.

Essentially, I would maintain that in these scenarios, project managers are making "claims", some even "vague claims", about the state of their project. That vague claim is made in the spirit of getting the boss off your back or in the knowledge (perhaps mis-directed) that by the time anyone checks ... the project will be where they have reported it to be anyway! It is done with good intentions.