Theories are different from hypotheses because they have been tested in a way that allows for understanding of cause and effect. To build a theory requires multiple tests that establish a plausible cause and effect relationship.

Theories have not been proven false. And so we must suggest in new hypothesis that will prove the claim or statements as false. Otherwise the theory can lead further deviation from an uneducated guess.

Choosing a theory might prove productive, but it can also be overly restrictive. I think it would be more useful to apply a hypothesis instead. This is really a qualified guess that you use to describe or explain a historical reality. Then you delve into your primary sources and discover if the the hypothesis is valid or not. If you're at the beginning of your research journey, you will quickly discover that you're off target. By a mile. And it's fine -- this is the process of discovery. You just learn, re-adjust and formulate a new hypothesis. And repeat... If you're stuck or frustrated, it might be useful to talk to the archivists. They might not be experts on the subject but they're familiar with the records.

Archival science has its own theoretical developments, which may be useful to you. It is also necessary to build bridges with other information/communication sciences or disciplines (library science, documentation, computer science, etc.) as well as take advantage of theoretical developments in the social sciences, such as history or anthropology

Yes. Try modeling the Wikidata base system .it is very cool when you can modulate in new functions. Mmm. These strategies just refine technologies when manipulating sets of data.

What about controlling for variables like space and time. How does the query in for information behave ? Can we shape data just by being around it. Is not this always biased ? Or continuous ?

Content validity. Null and void? Missing Data? language barriers? Under what categories , is it significantly important ? Hmmm u need to go back into thia

For the search, analysis and citation of sources, it is good to base yourself on the classifications of archival science, but also know how to open yourself to other classifications and types of sources studied by history, anthropology, archeology, computer science, etc. For example, the use of oral sources or non-written materials

Archival sources are usually cited from specific to general. For example, a citation for a letter would contain the date, correspondents, file number, series, the fonds title (ex. John Doe fonds), accession number, and archival institution. If some of the information, for example date or sender, is unknown or not clear, you can skip or indicate the lack of information with square bracket insert. Check you style manual for proper punctuation and citing conventions.

It is important not to underestimate or leave out of the analysis the material aspects of the archive studied (type of paper or other support, state of conservation, possibilities of digitization, etc.)