Root: Those are presented as 7 discrete points along a single dimension axis, i.e. a shade of gray type of categorisation.
The video above explains nicely that agnostic is not the state in the middle, but its an orthogonal dimension. Someone can be agnostic theist and there are also non-agnostic atheists.
The Dawkins' Spectrum is adequate because it encompasses everyone's views on God. Those who call themselves agnostic theists would be a 2 or 3. As for the gnostic atheist, it depends on how "know" is defined. If he defines "know" as absolute certainty, then he would be a 7. If knowledge instead accounts for the possibility of incorrectness, then he would be a 6.
I have a problem with the entire definition of "knowledge" because its definition varies so significantly depending on who is using it and what the context is. In the everyday context, knowledge is simply strong belief that can be wrong. For example, one might say "I know I will be home in an hour" when they feel highly confident that they will be home within an hour, even though it is possible that they will arrive later. In the context of philosophy, however, knowledge is often defined to be absolute certainty. An adherent to solipsism could say something like "I cannot know that anything exists" because knowledge would be defined as absolute certainty beyond any doubt whatsoever.
What's even more problematic is that both of these definitions of knowledge are incompatible with a 2-axis view of theistic plausibility, with one access representing belief and the other representing knowledge. If knowledge is defined as strong belief, then it would obviously fall on the same access as belief. If knowledge is instead defined as absolute certainty, then the terms "gnostic" and "agnostic" have no need to even exist because only the severely deluded would actually claim that it is absolutely and strictly impossible for them to be wrong.
What I like about the Dawkins' Spectrum is that it avoids the word "know" altogether. It's much clearer this way.
