While looking at this vast series of alternatives one also sees the instructors. I use that method. However, the widest taught model is not the only or necessarily the best model. There are many other models taught, both in Texas and at major universities, as well as in some foreign countries. This has led to a flood of mediators with vastly different methods, abilities and experience, all marketing themselves to a relatively inexperienced market.
Certification is seen as a way to reduce competition and desaturate the markets.
Enforcing a single mediation model. From billing methods to caucus styles, there are some sharp disagreements. A number of truly awful and repugnant individuals have set themselves up as qualified mediators. Certification is seen as a method of weeding these people out that is faster than other methods. A number of mediators subscribe to the board certification model and feel it will give them a credential that has a value as a reflection of professionalism.