Provisional personas are a small step towards empathy, but you're kidding yourself if you think they are a substitute for actually observing a real person. I liken them to stick figures, while a real persona would be a photograph. One is completely subjective, and the other represents an objective reality.
I'm amazed at how much effort designers, developers and engineers put into building stick figures that can't withstand the scrutiny of observation. Provisional personas are founded in intuition, not observation. Building from intuition is a risk ridden way to bring products to market.
3 reasons for building real personas
1. Real personas expose the flaws in your assumptions and intuition. Exposing your ideas to reality can be a scary thing, but how else are you going to know if the ideas have merit? Sure, spend countless hours and hoards of money building a product for an imaginary stick figure… which is more scary?
2. Real personas constrain competing agendas during the design and build process. Having observed reality gives you a solid position to design from. You can confidently defend a behavior, attitude or action when it truly exists. Subjective, provisional personas, crumble to competing agendas because they are so easy to undermine with opinion.
3. Real personas uncover new opportunities. Quite often, observing a fellow human being in action and understanding their motivations behind those actions will uncover opportunities you had no prior visibility to.
**Stop using provisional personas to build products! Getting out of your own head not only helps reduce the risk in bringing a product to market, but it also uncovers opportunities you never saw coming! **
Need help building a real persona? "Transforming Demographics into Personas" is a good place to start!