Conviction is the state in which you are convinced by someone's motives, actions, and prospects. Conviction is a sum of both your logical and emotional backing.
The logical backing is comprised of someone ticking off a list of needed conditions, despite lacking in certain conditions. The framework should be that as long as the needed conditions are fulfilled (downside risk), and the lacking conditions are understood and acceptable (risk management plan for other downside risk), then someone should pass the logical test.
It is illogical to expect that all conditions are equally important, and equally illogical that all conditions will be fulfilled. Both cases exist only in theory, and reality is much different. In reality, there will always be a condition that is more important or not fulfilled.
The emotional backing is comprised of someone ticking off your list of values you deem important. That list of values will vary from person to person, industry to industry, stage to stage, but probably only slightly.
Evaluating emotional backing is difficult because everyone will have different interpretations of what values mean. For example, whether someone has "learnability" is a function of how much time is spent with that person (is it at a distance or up close) and in what context (is this 2 years ago or 2 months? What situation was this in?). Thus, this indicates how difficult evaluating emotional backing is; the values that are assessed are all similar, but the interpretations can and will be tremendously different.