Comprehensible Input

From Learn Any Language

Comprehensible Input is language content which is understandable to the learner. Language learning only takes place when presented with comprehensible input -- if you were stranded on a desert island for 20 years with a radio that broadcast only Mandarin you wouldn't learn anything because the language is not _comprehensible_ to you.

Thus, for self-directed language learners, the idea is to find input at your level or slightly above -- context will make the unknown bits comprehensible.

Graded readers and Assimil both have this feature.