Dummies Question - 3 Furlong Workouts

[BigBlue]

Over the years, I've started to pay more and more attention to workouts and how they can help my handicapping. Most seem to be of the 4f variety - and when I see strong 5 and 6 furlong works I look at those closely.

My question is how much consideration should I give the 3 furlong work?

Why do trainers opt for the 3f vs 4f - are they trying to accomplish something different with one versus the other?

If you're preparing for a 6f or longer race, is there anything to be learned from a 3f workout?

Just looking for some opinions.

Thanks.