Does it Apply Everywhere?

When someone gives you advice, make certain it is applicable to where you are actually researching and the time period in which you need.

Recently a poster to a mailing list made generalizations about a certain type of record. What he said is true about New England, but it’s not true about points west of the Northwest Territory. Consequently if I were researching in Kansas and used his approach, I would be confused.
The problem is that some people don’t know their knowledge only applies in certain places or are unwilling to admit that they don’t know everything.