Currently we focus on the beta test of the functionality in the Stackz 07 beta version. Algorithms may be added at a later point in time if they are needed. We don't have any concrete schedule at this point in time.
Please note that the Stackz fundamental function is to give an accurate picture of the proficiency state of all cards at one glance, and the algorithms (mainly RepeatAdvisor, and the other ColorModes) are placed on top of this visualization, intended for making automatic use of the classification if no manual processing is wished. This makes Stackz different from other applications that use an algorithm as their fundamental function, without visualizing the state: The Stackz main function is independent from the algorithms. This is useful if a manual interaction is needed (e.g. real-world constraints like exam dates have higher priority than theoretic perfect learning). Also, we can add new algorithms quite easily if needed without interfering with existing functionality.
For example, a "fail" is a fail, but when we get a kanji correctly there is a big difference between something dredged up with great effort, something that takes medium effort and something that we know so well it is akin to breathing.
Concerning the extended fail/pass function: This corresponds *somehow* to the 5 levels in Stackz where the cards will eventually be accumulated. Not in one single classification, but after several classifications, the unknown cards will be on the left and the known cards on the right. Thus, in Stackz, the cards are truly characterized, and classified according to their nature, not according the next scheduled review. This gives you a very good starting point for any operation, e.g. "learn unknown cards" or "refresh known but old cards". These are fundamentally different tasks, with different levels of effort even if they are recommended for the same day.
So what happens in reality, is - as always with Stackz :-) - you know what you are doing:
- If you learn cards from the left side, you will probably not be so strict to yourself, and promote it easily.
- If you repeat the cards from the right side, you will probably be more strict to yourself.
- If you refresh an old file, without any ambitions of perfection, you will be less strict that if you prepare for an exam.
- If you use the RepeatAdvisor, you know why you are using it and what level of proficiency you aim at.
I would love to see a more sophisticated algorithm implemented in Stackz (in addition to the current modes). I want to keep using Stackz but these more sophisticated SRL systems are tempting me away. I'm sure the same is true of other users and potential customers.
Check those tools out, and see what is best for you. Preferences for tools differ in the same way the learning styles differ.
But what algorithm exactly would you wish?
Generally speaking, we believe that one should not try to find exaggerated precision in the whole process. The two difficulty estimations that can be used as basis for the RepeatAdvisor (promotion level, and success ratio) along with the assigned repetition delay are already very sophisticated. We are convined that what helps in reality is a simple tool that serves as a reminder for the constant learning actions, that will show you where your weak spots are, that will motivate you to continue improving your skills and somehow reward you for your efforts. All those things together bring value to the student, not the perfect moment for repetition alone.
Note:The extended fail/pass function, translated to the Stackz world, would be a "directly send to level x". This would speed up the classification, but at the cost of lower accuracy (the success ratio is based on repeated tests). In addition, the user interface would become more complex, which we try very very hard to keep at an absolute minimum. But this has been requested before, and if more people wish it, we will introduce that one day. But not in the next release :-)
