A respectable language learning program must expose students to a rich target-language environment. It shouldn't be so rich that the student is overwhelmed and "turns off", nor should it be so simple as to either not push the student, or be reducible to a list of words to master. Proper abundant exposure to the target language is, or ought to be a fundamental consideration of any (language) learning program. Swap 'discipline to be learned' for 'target language' in the previous sentence, and the same holds true for any educational program. The ideal level is perhaps best expressed by the popular 2nd language acquisition notion of "i+1". 'i' represents the linguistic level of the student (in the target language), and '+1' suggests that the program is a small push beyond that (too small or too big and students turn off). Noted language acquisition scholar Stephen Krashen says it like this: "[Language][a]cquisition is brought about when you talk to acquirers so that they understand the message, and when the input includes a little language that is somewhat beyond them." Comprehensible input, my esteemed associates, is a (if not the) holy grail of language learning.
There are numerous ways to make language comprehensible. A couple examples are diglot weaves and demonstration lectures. In diglot weaves, a student's native language is weaved together with the target language so as to provide a comprehensible context. The "stuff" that can be weaved ranges from individual words (When the boy was younger, he would often pick his nariz. This disturbed his parents, who told him it was bad manners for a boy his age to pick his nariz in public ) to language structures--so if a student is a native English speaker learning Spanish, the teacher speaks mostly English but according to a Spanish structure (the hombre no has the desire to eat the sandwich) Another example is a demonstration lecture. The idea is a lecture whose meaning is at the same time demonstrated, the meaning is clear because of the context, and the language simply accompanies. For example, imagine I have a white paper, a yellow paper, a white pencil, and a yellow pencil. I could say something like this (all in the target language): "This is a sheet of paper. This is also a sheet of paper. This is a pencil. This is another pencil. This paper is yellow. This pencil is also yellow. This paper is white. It is not yellow. These two are pencils. These two are papers..." In both of these examples, the underlying principle is bridging from familiar to unfamiliar. In diglot weaves we bridge from the familiar native language vocabulary and structure to the target language. In demonstration lectures, we bridge from familiar objects and descriptions to their expressions in the target language. We also avoid drilling vocabulary and phrases outside of a meaningful context. A more traditional approach would be to give students a list of words and phrases and demand that they memorize them. By being deliberate about making a rich "i+1" situation, we can delve into a richer linguistic environment, retain a comprehensible experience, and avoid the drudgery that typifies most language learning programs.