I would suggest a triangle structure. The bottom left corner represents
definitely true statements, and the bottom right corner represents
definitely false statements. (Maybe nothing will be in these absolute
locations, just varying degrees between). The higher up the triangle, the
less evidence is available to make a decision. As you reach closer and
closer to having no evidence, a belief can not be as far to the right or
left as it could have been if more evidence existed. An example. The
earth is flat, is very likely to be a false statement, based upon perceived
evidence (shadow on moon, change in horizon from height, pictures from the
moon), and therefore would lie close to the bottom of the triangle, and
close to the right side; very near the bottom right corner. A statement
like "God created man and the earth and the stars" has no evidence for or
against, and would be higher towards the top of the triangle. If you
define God to be a completely imperceivable entity, than a statement about
his existence would have to be at the top of the triangle, with no evidence
to sway it towards either side. i.e. more or less likely to be true.