Their establishment depends, first and most obviously, upon the _number of syllables_ in the series presented to the observer. While he can recite correctly, after a single reading, a series of 6 or 7, a longer series simply throws him into confusion. The first and last terms have a definite advantage; they may, indeed, be the only syllables that can be repeated after a single reading of a 12-term series. Secondly, the tendencies are strengthened by _repetition_. The first reading is more important than any other single reading; after that, there is for a while little if any improvement; then the results take a sudden step up; and thenceforward progress is fairly steady until the limit of the experiment is reached. Thirdly, the tendencies are furthered by a _grouping_ of the syllables. The observer learns a series more quickly if, for instance, he throws it into a rhythm. Fourthly, it is important to _distribute_ the readings in time. Two readings a day for 12 days give better results than four a day for 6 days, or eight a day for 3 days, although the total number remains the same. Fifthly, the _rate_ of reading has its effect; the syllables must not follow one another too fast or too slowly. There are great differences between individual learners; but we may say in general that the syllables should at first be presented at a moderate rate (perhaps two in the second), and that the rate should be slowly increased as the readings proceed. Sixthly, not only repetition itself, but also the _manner of repetition_, makes a difference. Meaningless syllables are learned somewhat better if the whole series is read through, over and over, from end to end, than if they are taken a few at a time, in small lots. Lastly, _recitation_ or reading aloud is ordinarily more effective than silent reading; largely, perhaps, because the separate pronouncing of every syllable equalises attention; every term of the series is brought out sharply and clearly, and there is no chance to slur. Here, however, we must remember the differences of imaginal type (p. 138); and it is true that a markedly visual learner will profit less by recitation than an auditory-motor learner. These experiments have, indeed, revealed other typical differences between individuals, such as those of _slow and quick_, and of _receptive and ingenious_ learning. Some of us, it seems, are naturally quick, and some are naturally slow learners, just as some work best at night and others in the morning. Some observers, again, accept the series of syllables, passively and without question; others embroider and interpret the meaningless forms in all manner of ways; _mon_ becomes man, and _kig_ king, and _wer_ where, and so on. We know nothing at present of the correlated differences in the nervous system.