Even more dangerous than these isolated courses are the schools claiming to teach self defense that have absolutely zero real-life experience, because now their students are developing horrible habits and muscle memory over an extended period of time while also increasing their confidence to unreal proportions. Some even use fancy keywords such as "Combat" or "Krav Maga" to draw in new customers (true Israeli military grade Krav Maga is a beautiful, effective hand-to-hand fighting system, unlike what is taught at most shopping center schools). More often than not, these instructors took some crash certification course themselves and now are Certified Level X Instructors in the "most advanced, deadly Marine Special Operations (wink) system of make believe combat." Some are just regurgitating the same ineffective techniques shown to them by their instructor as they were coming up through the ranks, based mostly on sport fighting techniques that have no place in real combat.
Now I must say that this article will not be which system teaches the most effective self defense. As stated previously, every system is limited by the range of the human body on how we can physically harm another person. Therefore, every system has the capability to be highly efficient in combat. It's the training methods and application of the physical techniques that determines the efficiency of what you're teaching for self defense.
The biggest thing you must overcome is your own adrenaline. Learning techniques in a static format is great for building muscle memory, especially if the training emphasizes the use of principles over rote memorization of technique, but you must work under duress. You could be the greatest technician in the world when demonstrating techniques, however if you panic when it becomes live you're as good as dead. I'm not saying your instructor must slam you into the wall daily, holding a loaded gun with live ammunition to your head while screaming degrading comments, but if you don't train with at least a little eminent danger you will never be able to overcome the body's natural responses to a life-or-death situation and remain in complete control. There must be a split second in your training where you go "Oh sh*t" and move for real, or you're just building false confidence. This type of training must be done on a regular basis in order for you to develop the adrenaline control necessary.
To add to the realism, in my school we occasionally use live weapons for weapon disarms. Of course, the attacker must have complete control of the weapon to prevent any accidents (which is why more often than not I personally am the attacker for my students when using live weapons) but if all you train with is an orange rubber gun and wooden knife, the moment you are confronted with something real you will freeze, if even for a split second. It's human nature, and that split second just cost you your life. When I say live weapons I mean pocket knives, steak knives and butcher knives for knife disarms, and airsoft guns for firearm disarms (students wear safety goggles). Never bring a loaded firearm with live ammunition onto the training floor for any reason. I must clarify that the use of live weapons is only for advanced students, while less those experienced perform the same drills in real time with simulated weapons.
DISCLAIMER: DO NOT BRING LIVE WEAPONS ONTO THE TRAINING FLOOR WITHOUT BEING PROPERLY TRAINED IN THEIR USE BY A SPECIFICALLY CERTIFIED INSTRUCTOR. WE ARE NOT RESPONSIBLE FOR ANY INJURIES OR DEATHS THAT OCCUR DURING YOUR MARTIAL ARTS TRAINING IN RESPONSE TO THIS OR ANY OTHER ARTICLE.