A good reader changes his reading speed
according to his purpose and to the difficulty of the material on the page.
When he reads easy material for pure entertainment,
he reads as fast as he can and probably gets all the meaning he needs.
But when his purpose is to learn something and there are hard spots in the material,
he slows down as much as he needs to so that he can understand what he reads.
Slowing down for difficult passages does not mean working along at a word-by-word rate.
In fact, no matter what your reading purpose may be,
you will cover the material faster and understand it better
if you learn to take in a group of words with each glance.