In order to advance a martial science, we must utilize a scientific lens and consume information in such a way that validity is determined. Let’s take a look at the different types of validity and create examples of how to apply those to martial science. My intent here is to crystallize our understanding of how the scientific perspective can be applied to martial-based movements and hopefully guide students who are seeking the martial science perspective. Although martial science does not look the same as the testing of a new personality inventory or quantum theory, I believe most of the principles of science that guide chemistry, psychology and biology can also guide us in our pursuit of martial science and more theory-based movement principles.
To start, consider construct validity. This essentially is the degree to which a test, theory or system does what it is intended to do. For example, an intelligence test that measures social skills would have LOW construct validity. In martial science, construct validity is the degree to which a movement actually works to defend the body from attack. Some martial arts look more like acrobatics, dances or impressive displays of physical strength that do little to protect the body from real-world violence. So if a martial system is constructed in a way that it is effective against various forms of real-life attacks, the system would have high construct validity. Adding to a systems’ construct validity, police, military or other real-world practitioners should be able to assess the movements of a system as having real-world self-defense application.
Face validity means that a lay person should be able to look at a system and say that it intuitively appears to accomplish what it is intended to accomplish. In martial science this implies that one not need be an expert or even familiar with martial sciences in order to see how a system would be effective in self-defense. Face validity is the degree to which the movement is intuitively correct to a naive observer. In some sciences, face validity is not really important. For instance, if I look at Einstein’s theory of relativity, it’s going to have low face validity for me–I can’t tell by looking at the formula that the theory is useful, however that doesn’t matter because my naiveté belies limitations in myself, not in Einstein’s theory. There are other sciences though where face validity matters very much, such as in sociology, psychology and yes, martial science. It is important to note that just because a system has face validity does not mean it is valid. Similarly, just because a system lacks face validity does not mean it is invalid. Face validity is but one aspect of the validity spectrum.

Content validity means that a theory or system stands up to testing from experts. A good martial system should provide movements that account for every type of attack, so a system that only is useful for, say, punches but not tackles or kicks, has low content validity. As I stated in my previous blog, if you are a martial scientist, you are always testing your system for weaknesses, flaws and inaccuracies so that the more effective systems can be pursued. In essence, you are seeking content validity from your system, and are hopefully open to others testing your system objectively and even critically as well. If you are a martial artist and are loyal to your system for reasons other than it’s tested effectiveness, then you are not seeking content validity.
To make an application for concurrent validity, I have to rely upon something I have said about my martial science perspective for over 40 years…”I extract what is essential from pre-eminent martial science systems”. Said differently, what WORKS is universal, and a good system should not contradict what has been proven effective in other systems. That being said, a system must also simultaneously have discriminant validity, which states that two systems should be discreet enough to be called TWO systems. In other words, a “new” system of martial science should not simply be an eclectic collection of movements that exist in other systems, it must offer something that other systems do not offer (otherwise what is the point of creating a new system at all?)
A system needs to have consequential validity as well–people should not be harmed by using a system, and if such harm exists, this points to some kind of invalidity of the system. I believe many people train in broken, martial arts-type self-defense protocols and then have a false sense of preparedness for a real attack or violent encounter. In my view, this is irresponsible on the part of teachers and creators of martial arts systems because we have a responsibility to train students as our system advertises. If you are teaching a non-scientific art, call it an art so that your students don’t get the impression that this training is going to be a fail-safe tool in a crisis encounter.
External validity is the degree to which a measure or system has applications across various users or situations. In martial sciences, this means that the system itself enables one to defend oneself, regardless of body size, strength, age, gender, etc. You may notice that some systems hide their flaws when the practitioner happens to be particularly strong or big, but that would be evidence of low external validity.
We, as practitioners, can contribute to the seeking of valid martial sciences by rigorously and objectively testing and re-testing the usefulness of movements against attacks. These systems should be tested against as many varieties of attack as possible, the testers of martial systems should be of varied body types, ages, genders and sizes. Those who test martial movement should embark upon this testing with the null hypothesis in mind: the intent is not to “prove” the system, but rather to disprove it, so the priority should not be to make the instructor “look good” or to make the system look effective–this is showmanship, not science. I encourage all who pursue martial science to bear the premises of scientific validation in mind in all teaching and learning endeavors, for this is the pathway of empirical strength and more effective systems.