|
Interlocking
Definitions
Consider
the sentence below:
The
male part of a flower is called the stamen which consists of a
long stalk called a filament which supports an anther, inside
which, pollen grains grow.
This
is a complex sentence and would probably not be presented to students
of a primary age. We can simplify the sentence by taking out most
of the relative pronouns 'which' to make separate sentences as follows:
The
male part of a flower is called the stamen. The stamen consists
of a long stalk called a filament. The filament supports an anther,
inside which, pollen grains grow.
We
could simplify the sentences further by changing substituting simpler
words for unfamiliar lexical words (information words). In this
case they are 'consists' and 'supports'. (See below for a discussion
of lexical words and lexical density). We can also separate the
last sentence into two simple sentences making sure not to use a
pronoun in place of the word anther. The sentence becomes:
The
male part of a flower is called the stamen. The stamen is made
up of a long stalk called a filament. The filament holds up the
anther. The pollen grains grow inside the anther.
The
sentences carry the same information but are now simple sentences.
However, there is still something that makes this information difficult
to understand. It is the way the definitions are presented in relation
to each other. Haliday calls these "interlocking definitions".
By this he means that the sentences depend on each other to make
sense. We cannot fully understand what a stamen is without understanding
what the filament and the anther are. In turn, we cannot fully understand
what filaments and anthers are without understanding that they are
part of the stamen.
No
matter how you attempt to write this information, the problem will
still exist simply because the anther and filament are part of the
stamen. Also, it is the filament's job to support the anther and,
therefore, it cannot be defined fully without reference to the anther.
Interlocking definitions are common, particularly, in texts which
describe the relationship of parts to whole. (See
parts whole).
There are ways to address the difficulties inherent in writing which
contains interlocking definitions. It is important to point out
that it is unlikely that the information in the above sentence would
be presented without a diagram. If it was, then it would have to
be much more detailed in order that students are able to appreciate
the shape, size and position of the parts mentioned. The students
can be provided with a labelled diagram as shown below:
These
diagrams draw our attention to some of the problems associated with
presenting diagrams to students. The first two diagrams (Figures
8 and Figure 9) may be appealing but are of limited value since
they do not emphasise the different parts of a flower very clearly.
Also, the labelling is not helpful. It is not clear whether an anther
is the same as a stamen or whether they are different. The second
two diagrams are what we might expect to see in a science book.
Notice that there is no explicit label for the stamen because a
stamen is made up of an anther and a filament. (This information
can be recovered from the sentence.) Also, both diagrams attempt
to show cross-sections of a typical flower but the black and white
diagram is a fairly abstract representation of a flower; it would
not be obvious that it was a flower if presented out of context
and/or with no labels or title.
For
a more detailed discussion of diagramming in science see  Composition.
Back
|
Literacy