The term "comprehension" has become a "catch all" item. If a student is failing in school, his teacher will probably tell you that he does not comprehend what he reads. In addition, the teacher may mention that the student gets more from just listening than he does from reading. Another teacher will tell you that a student reads well in his social studies book but cannot quite figure out his math problems. Yet another teacher will tell you that one of her students comprehends when there are pictures on the page but take the pictures away and the student is lost.
Rakes, T. (1972). The Comprehension Dilemma. Reading Horizons, 12 (2). Retrieved from http://scholarworks.wmich.edu/reading_horizons/vol12/iss2/5