Anecdotal Evidence

[RoadRunner79]

Depends how you define knowledge. It's not a simple concept. If you're interested in the most accurate models of reality that can be found, then yes, you use the scientific method. If you're examining something for which you can no longer do any testing, you have to draw your best conclusions from the available data. You still use a scientific method as far as possible.

I have no idea what else you're suggesting, or what kind of knowledge you're talking about. I can gain informal knowledge just by observing things. If I want to confirm that what I think I know is as accurate as possible, I'll use scientific methods and independent observers to review my work.

Scientific methods are those methods which can be demonstrated to produce reliable results. So if you have some other method, either it also does this and so is science; or else it doesn't and it's probably not very useful. Trying to say something isn't science but does what science does is equivocating.

An example would be nice, please. Because all I have to go on at the moment is your beliefs about religious documents.

You may want to clarify, when you are talking about science, what you mean.   What you are saying here, sounds very much like an old definition of science, when philosophy and theology where considered science, and most modern readers are going to have a narrower definition in mind if you are not clear. 

You had mentioned, that one can gain informal knowledge by observation.   This is my point.  Seeing something is a basic principle, there is no other reason needed, to justify belief (although interpretations may questionable).  You don't need to understand it, or to be able to repeat it.   And like other knowledge, this information can be transferred to another.   It is evidence (or a reason to believe that a proposition is valid). 

For example, from science, I am very doubtful about life on other planets. The conditions for life, appear to be highly improbable, and quite restrictive.  As well, there are a number of hurdles, in traveling to a very distant planet.  However, if a number of people are attending some outdoor event, and all give similar detailed reports of a craft coming down, and taking one of the people at the event.  A number of people who know the person who was taken also report him being missing.   Three days later he is found, and gives a detailed report of the aliens who took him.  The craft left no other physical evidence which can be found, and there are no photos or videos from the time of the event. 

The event cannot be repeated, and nothing in the story is available for study.  However at the very least, there are a number of witnesses, who pretty much agree about the craft, and then there is the testimony of the one taken.  And further those who reported the person was no where to be found for the three days.  Now it is possible, that there could be other explanations, but without further reasons; these would likely contain many more assumptions as well.  At this point given the evidence, I would think that I would need to re-evaluate my assumptions based on science.