Students who have trouble concentrating and remembering what they read may have a passive reading style - they slide their eyes over the words and assume that somehow something will sink in. To read actively, comment on or ask yourself questions about points in the text. Look for main points and supporting evidence or examples as you're reading. Students who read actively remember the material better, and therefore are using their time more effectively. Using a reading technique like SQ4R can also help to make your reading style more active.
Many students are concerned about their reading skills, in particular their reading speed.
However, the speed with which you can whip through a reading is not nearly as important as whether the reading technique that you're using is appropriate for the task . The way you read a novel or newspaper should be different from the way you read a textbook. With a text that you're required to know thoroughly, a slow, careful pace is time-consuming but necessary for comprehension. It's difficult to convince students who value speed over comprehension that it's smarter to spend an hour on five pages and know the material well than it is to spend an hour on fifty pages and remember nothing. However, it's just as inappropriate to spend hours memorizing every detail of a chapter when all that's required is a general understanding of the main ideas.