Karaka Planets

Trying to understand karaka: if a planet is the karaka of a house and resides in that same house, does it make it's influence strong? Like Mars in 3rd or Jupiter in 5th, would they be especially strong?

Or do you look at the position of the karaka of a house in the chart to determine the strength or influence of that house? Can someone give me an example for this?

Karaka is not preferred in the relevant house. Karaka placed in VI/VIII/XII house from the house or owner of the relevant house is not good.
Karaka should be strong by usual standards.
Aspect of the karaka on the relevant house is good.
Karaka well placed and strong in the relevant divisional chart is good.