Authoring Foreign Language Textbooks/Bite-sized language lessons

Bite-Sized Language Lessons: An Idea for Content Improvement
A lot of the existing language course books unfortunately aren't very helpful to learners right now because they aren't very organised: since different people with different ideas contributed, each lesson might differ from the others in its approach, in what prior vocabulary/grammar knowledge it assumes or even what final study goal it pursues. Also there is a didactic problem: often the student is drowned in new things he has to learn in the course of a lesson in order to be able to progress.

Hence my idea for a new type of language courses in Wikibooks, which I already successfully used for German on my private website: courses using a "bite-sized" approach. In short, it means to prepare lessons in such a way that the student will be able to comfortably study one lesson per session and yet to allow him to learn more if he wants to by way of optional modules.

The basic structure of such a lesson:
 * Text or dialogue in the foreign language
 * New words
 * Grammar / word usage explanations
 * Exercise(s)
 * Exercise answers (for auto-correction)
 * Extra vocabulary for optional study

Additionally, the lesson may be interspersed with cultural notes and tips for learning - mnemonics and the like.

The goal of the course shall be proficiency level A1 as defined in the Common European Framework of Reference for Languages. Then more levels can be built with the clear goal of moving from A1 to A2, A2 to B1 and so on, which will allow for better splitting of tasks.

The lesson texts (at least for the first level) will be about common situations that learners may soon find themselves in and they will use standard everyday language. There should be no useless phrases such as "My tailor's son studies dasology"(true example from a commercial textbook!).

A lesson should aim to introduce just 10 new words but in no case should there be more than 15. More vocabulary can be offered in the optional module at the end and the interested student will browse through the optional vocabulary and learn anything he considers important for his personal situation. For example an Algerian person would probably want to learn how to say "Algeria" in the foreign language, but all other students can safely ignore that word until they are at a far more advanced level. In the lesson teaching how to say "I come from ...", "Algeria" and most country names would not be mandatory vocabulary to learn but they would figure on the list of optional vocabulary. The vocabulary taught should be oriented at the most common words in a language and avoid rare ones at all cost.

Similarly, there should not be much grammar in a lesson, not tables upon tables of conjugation to learn for example. Three or four short notes, covering half a screen in total, will be enough. Once a student is familiar enough with the grammar taught in one lesson and would like to learn more, he can move on to the next lesson. That not just ensures that nobody is overwhelmed, it also provides a feeling of success.

Of exercises there can hardly be enough and every lesson needs to include exercises; they are essential to understanding and learning of new grammar or vocabulary. Challenged students will need many opportunities to practise. Unlike in a classroom situation, this won't be a bother for good students because they can always skip some exercises and move on to the next topic.

I have started posting lessons using this approach for German here: BLL German

Help is of course welcome, particularly in wikifying the existing lessons from my website.

I have received nothing but good critiques for this and I really believe that people learning any language in self-study would benefit from such an approach.