Rank of any sort implies an ordering of skill or accomplishment. People of a higher rank are better on some scale than those of lower rank. Ranks are prevalent in many kinds of human endeavor, and yet there are different kinds of rank. In discussing what rank means, or could mean, in karate, we first examine other disciplines.
One kind of rank is an objective performance rank. It reflects the individual's performance on a task at one point in time. The Standardized Aptitude Test (SAT) is an attempt to create a test of this sort. There are right and wrong answers as determined by a panel of experts. Tests are marked automatically and the only subjectivity can be in how the test question is created in the first place. Once a question is designed, the scoring is objective. Such a test does not take into account the improvement (or degradation) of skill in a student over time. It does not have a subjective element in the evaluation itself. The test results in a total order of participants (except in the case of identical scores on a scale with several hundred possible points).
Ranking may be objective or subjective. There may even be multiple ranking scales for the same object or performance. If a Van Gogh painting get the record highest sale amount at auction is it therefore the "best" painting? The objective metric does not feel like the right one in an inherently subjective environment, yet there can still be many points of agreement about inherently subjective ratings. Many scales also have both objective and subjective components. Or subjectivity can be a pervasive quality that we are uncomfortable to acknowledge. The academic endeavor has an inevitable subjective component at every stage, yet we like to think of academic accomplishment as being an objective meritocracy.
When truly objective assessment is elusive, societies use groups of people, often themselves selected by rank, as a proxy for objectivity. An example is panels of judges for artistic endeavors like figure skating or dance. Groups are considered less likely to have random variation in the assessments they provide, or possibly less bias. This is of course often not true, but the presumption is that the group will give a more correct rank than an individual. This could however just be a result of human psychology that an individual can easily be argued with, but a group has more strength and authority. So a group authority is chosen over an individual authority as a social convention simply because the pronouncement of a group is more likely to be respected.
There is debate on whether academic tests reflect ability or accomplishment. The SAT is likely somewhere in the middle on this scale. Pure intelligence tests at least attempt to be a test purely of ability (intelligence). In contrast, scholastic achievement tests such as the Advanced Placement (AP) test attempt to target whether a particular syllabus has been learned. Of course, people can learn how better to take an intelligence test (learning) and people must have considerable intelligence (aptitude) to be successful taking an AP test. Many professional tests such as medical boards, the legal bar exam, the contractor's license exam, are all geared toward examining knowledge of a syllabus, but in the case of medical or bar exam, the standard is high enough to require a level of aptitude in the field, as well as knowledge.
Another sort of ranking is the degree system of western education. A PhD is given more value than an associate's degree, and employment solicitations and positions may require a certain level degree. Yet within degree classifications, and even in comparing degrees of different levels from different institutions, there may be considerable variation. Is a master's degree from a minor school really superior to a bachelor's from a top Ivy League school? There is an independent accreditation process for colleges, but one might say that only a bare minimum set of requirements are mandated, so that one has to look to the institution to assess the value of the degree.
Rank is sometimes its own reward. Positive reinforcement can lead to better performance, both in the activity and outside it. There have been frequent criticisms that western society is leaning too much in recent time to rewarding every accomplishment, no matter how small, and thereby devaluing real success and achievement. One approach is essentially to give everyone his own scale and reward individual improvement without comparison to other practitioners. Do we reward and rank the handicapped student who has shown incredible improvement with a greater rank than a talented slacker? Or do we give higher rank to the slacker, who, even while losing ability due to sloth may remain incomparably better than the diligent and untalented striver?
Intuitively, the karate student looks to higher ranks as being "better" at karate. However, practitioners are not demoted as they age or suffer injury or infirmity. It seems that knowledge and teaching ability continue to confer superior rank, even as the practitioner declines in pure physical skill. This is contrasted with sports where rank (such as a tennis or golf "seed" or chess competitor rank) is purely as a result of success in competition, and a number one seed can quickly drop in rank after a few losses.
A complication however to this scheme arises with those who start karate late in life. A karateka who begins in middle age may not be able to attain advanced rank by old age. A high level of physical skill is not attained because of physical decline, and yet there has not been enough time to acquire a broad and deep range of martial experience necessary for teaching. Do we doom that practitioner to low rank because unable to attain a certain level of physical skill he or she is unable to advance past that kind of rank to a rank based on mature knowledge and teaching ability? Karate rank measures different things from low to high rank.
There are boxing coaches most notably, as well as coaches in other sports who have very limited success as competitors and yet may be at the top of their field as coaches. Might we completely decouple teaching ability and teaching rank from performance ability?
Modern karate already decouples rank and performance to some degree through tournaments. Competitors are placed into large groups. A Shodan can beat a Yondan at tournament and their ranks are unchanged after the competition.
Karate has many historical influences, including eastern religion and philosophy. We may ask to what degree history influences ranks, and to what degree it should carry such influence. Buddhist philosophy, especially in the soto Zen sect most closely tied to karate, emphasizes living in the moment, and giving up attachments to worldly concern in favor of an empty mind that can lead to enlightenment. Having goals and desires is at odds with this philosophy. Ranks themselves are very worldly attachments. The oral tradition of karate is that ranks are not the objective, just self-betterment. Ranks, in the historical tradition, were intended to help the teacher more easily organize students into groups for appropriate instruction. But that is not the modern reality.
We cannot say what rank should be until we can examine what it is for. Karate serves many purposes for the individual, and society.
Some possible individual purposes of karate are:
Rank already meets these goals, but it used imperfectly, and must be the subject of improvement and study for the authorities granting rank, as well as the measure of progress for the individuals receiving rank.