SuperMemo may be harmful when studying hard sciences
In my opinion, the most effective approaches to learning differ among both people and subjects. The best approach for person A to learning subject X is different from the best approach for person B to learning subject Y. For example, if I ever seriously decide to learn another language, I will reach for SuperMemo as the most effective tool I am aware of for extending my vocabulary in that language. However, I find SuperMemo utterly useless, even harmful, when studying math and theoretical physics. On the other hand, I don't exclude the possibility that for some people, SuperMemo may be useful in studying sciences (although, I would urge them to carefully re-consider before investing their time and effort given my personal experience, and the lack of evidence (that I am aware of) in successful application of SuperMemo to studying hard sciences). There is no universal tool, in my opinion, that works best for all people and all subjects. The idea is to develop one's own learning tool kit, so to speak, with tools that work best for learning various subjects/various fields. The tool kit may include mnemonic techniques, problem solving, designing examples, spaced repetition, practice of movements/gestures, etc. The more versatile the tool kit, the more chances of finding there an optimal approach to learning in a particular situation one encounters. And, the more opportunities for creativity. The only way to develop such a tool kit, as far as I know, is to try for yourself to see what works and what does not. Using experience of other people is also helpful. In the latter case, it is best to look at the people who are most successful at the subjects we are trying to learn--and try to see how the DO it rather than listen to what they say (about how they do it). In other words, you don't try to imitate a polyglot when learning biology, or Wozniak when learning physics, or yours truly when learning to swim.
Your reasoning is flawless as long as the phrase "I find SuperMemo utterly useless" is understood as "I find SuperMemo useless for me" rather than "I conclude SuperMemo is useless when ...". SuperMemo can definitely be harmful in learning. So can schools, books, teachers, movies, and other otherwise helpful components of education. Each time you say "as far as I know" and "in my opinion", you leave enough room for your statements to be general enough to be correct. Needless to say, at SuperMemo World, we (almost universally) agree that there are many "smart" applications of SuperMemo in *some* areas of math, physics, hard sciences for *some* people.
Nothing beats solving quadratic equations for the applicability of involved formulas in real life, however, for a student hard pressed for time, with interest in arts and photography, dry formulas in SuperMemo make it possible to revive associated skills at moment's notice at any time. He or she may naturally choose to Google instead (as long as the name and concept of "quadratic equation" still rings the bell). It is personal.
Please explain how SuperMemo can be harmful in your opinion. We are aware that many users form complex items in theoretical subjects (in violation of minimum information principle). Those items work well for a while until they are reduced to dry binary associations that bear little resemblance to the original. Such items may indeed be of little use and a simple drain on time. An alternative approach is to set the grading bar high and turn such items into leeches. Those are a double drain and the most effective tool discouraging the use of SuperMemo in areas more complex than vocabulary drills. It takes 1-2 years of solid practice to effectively use SuperMemo in more advanced areas of science. It is quite an art to know what to choose to know and remember. Most of all, effective formulation/representation of knowledge is essential. Last but not least, classical SuperMemo you know from vocabulary tests is quite remote to SuperMemo involved in problem solving. The proportion of items may drop to a tiny fraction of all elements. Sometimes it is more about information processing than memorizing.
- The role of incremental reading in learning hard sciences is discussed here: Incremental reading may hamper learning complex subjects
- Applications of incremental learning in problem solving and creativity are discussed here: Incremental learning: problem solving and creativity