When you are forming your hypotheses, go with the obvious answer first. You can always amend your theory later. Here are a couple of very simple examples:
If you see John Q. Citizen, age 32, living with Mary Jane Citizen, age 30 on the 1850 census, the obvious conclusion is that they were husband and wife even though the census doesn't say so. Yes, they could be brother and sister or some other relationship but go with the obvious until other clues come in that cause you to rethink your position.
John and Mary Jane Citizen were living in Perry County, MS in 1850, 1860, 1870 and 1880 per the census records. All of their children were born doing that time period. The obvious conclusion would be that all of the children were born in Perry County, MS. It is possible that Mary was visiting her sister in Marion County in 1864 when son Thomas was born but that is a more unlikely scenario. Again, you may find some evidence further down the road that leads you in that direction but for right now you can make the assumption that the children were born in Perry County.
“Perhaps, when a man has special knowledge and special powers like my own, it rather encourages him to seek a complex explanation when a simpler one is at hand.” [Holmes to Inspector Stanley Hopkins of Scotland Yard, "The Abbey Grange"]
“It is possible.”
“More than that. It is probable.” [Watson to Holmes and Holmes’ response, “The Five Orange Pips”]