Chapter 7, page 140
Figure 7.4b: Biology Passage Without Text Structure Cues
BIOLOGY OF THE VERTEBRATESSECTION 1: CHORDATES--The most complex form of animal life
The phylum Chordata contains the most complex animals that have ever lived on this
earth. This phylum has four subphyla. The largest and most important subphylum is the
Vertebrata. This subphylum includes fish, amphibians, reptiles, birds, and mammals.
Three factors make chordates different from all other animals.
- All chordate embryos have a rod of connective tissue along the length of the dorsal
side of their bodies. This rod is called a notochord. Primitive chordates have a notochord
their entire lives. So do some lower vertebrates, such as the lamprey. But the notochord of
the lamprey becomes surrounded by cartilage parts of the spinal column. In other
vertebrates, the notochord appears only in the embryo. But early in life, it changes into the
vertebral column, or backbone. - All chordates have a tubular nerve cord. It lies just above the notochord on the dorsal
side. The anterior end of this nerve cord develops into a brain. The remaining part
becomes the spinal cord. Together, the brain and the spinal cord make up the central
nervous system. - All chordata have paired gill slits at some time in their lives. These gill slits form
openings in the throat. Fish and the more primitive vertebrates have gill slits throughout life.
The higher vertebrates, including reptiles, birds, and mammals, lose their gill slits very early
in life.
Try reading the first version of the passage. You probably find it much more difficult to read and
understand than the second version of the passage. You probably use the headings and other signals in the
second passage to help you organize your understanding of the passage. Without headings and other cues to
text structure, the passage on the right is much harder to read.
Effective learners can be expected to learn a lot more from the passage with cues to text structure
than passage without these cues. Ineffective readers on the other hand, learn relatively little from either
passage, and they may learn no more from the passage with text cues than the passage without text cues.
Ineffective readers do not pick up on cues to text structure (Meyer & Rice, 1984). By teaching poor readers
how to use text structure to help guide their understanding, teachers can enable students these students to
improve their reading comprehension (L. K. Cook & Mayer, 1988; Meyer et al., 1980; Taylor & Beach,
1984; Williams, 2005).
Cues to text structure also alert readers to the overall rhetorical structure of the text (Deane,
Sheehan, Sabatini, Futagi, & Kostin, 2006). Rhetorical structure refers to the overall organizational
pattern of a text, such as the pattern of comparing and contrasting or the pattern of presenting a persuasive
claim with supporting arguments. Commonly used rhetorical structures are presented in Figure 7.5.
Researchers have found that even college students can benefit by being taught common rhetorical
structures. For example, college students who are explicitly taught how research reports are structured (see
Figure 7.5) learn more from reading research reports than students who have not been given explicit
instruction (Dansereau, 1985).