First, it depends upon your trading timeframe. It needs to be precise enough to give information but not to coarse to gloss over things. Also it depends upon what you use it for, e.g. Signals or actual order generation.
BTW: They are not the same thing, or at least should not be unless that is by design. If this is news, then figure it out how these two different actions triggers work in your system.
AND as everyone above says, it is easy to use it wrong-poorly. For example, using it for real-time decisions is a terrible idea. Worse to use it to justify things that should not be done. But to use it as a historical reference, it has its uses.
Hope that helps.