Visual focus . Students may not be able to concentrate on a particular textual item on a page crowded with printed text, and in a classroom their attention may wander. This ability to draw the learner's attention to a desired linguistic feature may be an advantage. On the other hand, presenting words and phrases out of context may be detrimental if learners lose sight of the total picture. Tireless repetition .
Computers are superb at handling repetitive tasks.
They can present the same material again and again at times when their human instructors are not available. Repetition plays an important role in any theory of language learning. The importance of repeated input has been mentioned by several researchers in second language acquisition. Repetition of input also plays a part in the attention to which it is accorded. From the standpoint of the instructor, it has been noted that the computer never loses patience with students, never gets angry, and never plays favorites.