What is the difference between these "distancing expressions"?

It's more a constellation than a continuum, but here's what I would say:

• allegedly (we are distancing ourselves from responsibility for something)
• purportedly (someone else has responsibility for it)
• seemingly (I take some responsibility for the evidence given me by my senses)
• supposedly (other entities have indicated it might be true, which I may or may not agree with)
• ostensibly (an assertion has been made, and I'm making an inference about that)
• putatively (someone has applied a label to a thing or situation and I may or may not agree that it is apt)

I thought about trying to put these in order, but I can't. The words aren't really a progression.